"Remote" tab missing in My Computer properties

Article Source:http://windowsxp.mvps.org/remotetab.htm

When you right-click My Computer icon in the Desktop and choose Properties, the Remote tab may be missing. As a result, you may be unable to configure the Remote Assistance / Remote Desktop settings. To restore the tab, follow these steps:

Click Start, Run and type this command:

regsvr32 %systemroot%\system32\remotepg.dll

If you receive an error stating that the module could not be found, or stating no registration helper is registered for this file type (which indicates a corrupt DLL), extracting a new copy from XP CD should help. Make sure that you extract the updated copy of the DLL file if you have applied the XP Service Pack in your system. Register the DLL again.

(Extract the DLL from a Slipstreamed XP CD, or copy the remotepg.dll from ServicePackFiles\i386 folder to Windows\System32 folder)

To extract the DLL from Windows XP CD, type this in Command Prompt

EXPAND X:\I386\REMOTEPG.DL_ -R C:\WINDOWS\SYSTEM32

Where X:\ is your CD-ROM drive letter. The above command assumes Windows is installed in C:\ drive. If not, change the drive letter / Path accordingly.

Example

EXPAND H:\I386\REMOTEPG.DL_ -R G:\WINDOWS\SYSTEM32

VirtualBox Installation crashes with 'IOError: [Errno 30] Read-only file system'

Recently I tried to install Redhat Linux in Virtualbox, however I got the below error.




By default the hard drive I created was a SATA HD, the workaround is to create a IDE hard drive instead and make it as Primary Master ID. This could be a bug in Virtualbox

OpenWRT for TL-WA801ND V2

I bought a TL-WA801ND router with version 2.1, unfortunately DD-WRT doesn't support it and OpenWRT only support version 1. After a few hours googling and retrying, I finally had the OpenWRT installed onto the router.

Thanks to TasksOfOhm who provided an awesome tutorial and binaries for TL-WA801ND. Please refer to the below link for more information:

• Bringing OpenWRT to TL-WA801ND v2 (Part 2, Building OpenWRT)

Go to the link below to download the binaries:

• OpenWRT TL-WA801ND-v2

I downloaded below ROM and flashed it into the router using the original web admin interface.

• openwrt-ar71xx-generic-tl-wa801nd-v2-squashfs-factory r41150.bin (12/06/2014)

Below are the errors I had and the ways to fix it. Please note that if you download a different ROM other than r41150 you may not experience the below errors

After the router is flashed and rebooted, I typed in 192.168.1.1 and got the below errors:

• /usr/lib/lua/luci/dispatcher.lua:211: /etc/config/luci seems to be corrupt, unable to find section 'main'
  stack traceback: [C]: in function 'assert'
  /usr/lib/lua/luci/dispatcher.lua:211: in function 'dispatch'
  /usr/lib/lua/luci/dispatcher.lua:195: in function

The above error occurred because /etc/config/luci does not exist. You will need to create this file yourself. To do this:

1. Telnet 192.168.1.1 to access your router. By default, telnet access is enabled and ssh is disabled so no pasword is needed. Please set the password here then access it via ssh
2. create /etc/config/luci file and copy the below content in:
• config core 'main'
          option lang 'auto'
          option mediaurlbase '/luci-static/openwrt.org'
          option resourcebase '/luci-static/resources'
  
  config extern 'flash_keep'
          option uci '/etc/config/'
          option dropbear '/etc/dropbear/'
          option openvpn '/etc/openvpn/'
          option passwd '/etc/passwd'
          option opkg '/etc/opkg.conf'
          option firewall '/etc/firewall.user'
          option uploads '/lib/uci/upload/'
  
  config internal 'languages'
          option en 'English'
          option 'zh_cn' 'SimpChinese'
  
  config internal 'sauth'
          option sessionpath '/tmp/luci-sessions'
          option sessiontime '3600'
  
  config internal 'ccache'
          option enable '1'
  
  config internal 'themes'
          option OpenWrt '/luci-static/openwrt.org'
          option Bootstrap '/luci-static/bootstrap'
3. Save the file and retry visiting 192.168.1.1, now I am getting
•  

  /usr/lib/lua/luci/dispatcher.lua:284: No valid theme found
  stack traceback:
   [C]: in function 'assert'
   /usr/lib/lua/luci/dispatcher.lua:284: in function 'dispatch'
   /usr/lib/lua/luci/dispatcher.lua:195: in function 

To resolve the problem we need to reinstall luci-theme-bootstrap.

•  luci-theme-bootstrap_svn-r10375-1_ar71xx.ipk

 Download the above package and upload it into the router /tmp. You can use WinSCP to upload the file. Remember to set WinSCP to use SCP protocol, not FTP or SFTP. Also in the Advanced configuration pane, need to disable Environment => SCP/Shell => Other Options => Lookup user groups

SSH to your router /tmp, and run below command

•  opkg install luci-theme-bootstrap_svn-r10375-1_ar71xx.ipk

Revisit 192.168.1.1 you should see the OpenWRT web interface

Build failure using gradlew: "Could not resolve all dependencies for configuration ':app:_debugCompile'

I was trying to build my project with Gradle in Android Studio, then I had the above error.

To resolve this I had to use the Android SDK Manager to install "Android Support Repository". After that the project was rebuilt successfully.

Outlook unable to search emails downloaded from Google Apps Sync

If you have Google Apps Sync installed to download the emails from Google Mail and you are not able to search the emails, the method below may help you to resolve the problem:

Environment: Windows 7 + Outlook 2010
Problem: Try to use the search box within Outlook to search the emails, it keeps giving nothing and the index status is showing nothing to be indexed

Locate the following registry subkey:

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search

Double-click the PreventIndexingOutlook registry entry.

In the Value data box, type 0, and then click OK.

If the above registry subkey "Windows Search" is not there, please create it and create PreventIndexingOutlook entry in there and set it to 0.

Exit the Registry and try to search now in Outlook.

Reference: http://support.microsoft.com/kb/972814/en-au

can't open or create /var/run/crond.pid: No space left on device

This error message told us that there is no disk space left on /var

When we run "df -h" on the system we get:

[root@A5AFETTASB pats]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/cciss/c0d0p3     3.0G  1.7G  1.2G  59% /
/dev/cciss/c0d0p1      99M   15M   80M  16% /boot
/dev/cciss/c0d0p6      24G  5.9G   17G  27% /opt
none                  1.3G     0  1.3G   0% /dev/shm
/dev/cciss/c0d0p5     2.0G  1.1G  790M  59% /var

Seems like only 59% disk space is used but that is not true. As the difference here is MB of space versus the almighty inode. So if we try using "df -i", we get:

[root@A5AFETTASB pats]# df -i
Filesystem            Inodes   IUsed   IFree IUse% Mounted on
/dev/cciss/c0d0p3     393600   95644  297956   25% /
/dev/cciss/c0d0p1      26104      40   26064    1% /boot
/dev/cciss/c0d0p6    3123232   12620 3110612    1% /opt
none                  322278       1  322277    1% /dev/shm
/dev/cciss/c0d0p5     262144  262144       0  100% /var

Further investigation showed, there are huge number of files created under /var/spool/clientmqueue that caused the problem:

[root@A5AFETTASB pats]# du -h /var/spool/*
4.0K    /var/spool/at/spool
8.0K    /var/spool/at
1.1G    /var/spool/clientmqueue
12K     /var/spool/cron
4.0K    /var/spool/cups/tmp
8.0K    /var/spool/cups
4.0K    /var/spool/lpd
8.0K    /var/spool/mail
4.0K    /var/spool/mqueue
4.0K    /var/spool/repackage
4.0K    /var/spool/rwho
4.0K    /var/spool/samba
4.0K    /var/spool/up2date
4.0K    /var/spool/vbox

If you don't care about the content you can simply delete the files, but you should ask yourself why you have tons of messages in that directory.

# rm -rf /var/spool/cilentmqueue
# mkdir /var/spool/cilentmqueue
# chown smmsp:smmsp /var/spool/cilentmqueue

If the emails are the result of crontab, below will explain how to disable it:
http://www.cyberciti.biz/faq/disable-the-mail-alert-by-crontab-command/


In this case the problem caused by sendmail. If you don't use it we can just disable the service


# svcs sendmail
STATE          STIME    FMRI
disabled       Sep_15   svc:/network/smtp:sendmail

Or you should probably enable it just to make sure that at and cron job output is delivered.  You can configure sendmail such that it doesn't accept remote SMTP connections.

How to block/unblock an IP from Linux?

In order to block an IP on your Linux server you need to use iptables tools (administration tool for IPv4 packet filtering and NAT) and netfilter firewall. First you need to log into shell as root user. To block an IP address you need to type the iptables command as follows:

Syntax to block an IP address under Linux

iptables -A INPUT -s IP-ADDRESS -j DROP

Replace IP-ADDRESS with your actual IP address. For example, if you wish to block an ip address 65.55.44.100 for whatever reason then type the command as follows:

# iptables -A INPUT -s 65.55.44.100 -j DROP

If you have IP tables firewall script, add the above rule to your script.
If you just want to block access to one port from an ip 65.55.44.100 to port 25 then type command:

# iptables -A INPUT -s 65.55.44.100 -p tcp --destination-port 25 -j DROP

The above rule will drop all packets coming from IP 65.55.44.100 to port mail server port 25.

CentOS / RHEL / Fedora Block An IP And Save It To Config File

Type the following two command:
# iptables -A INPUT -s 65.55.44.100 -j DROP
# service iptables save

How Do I Unblock An IP Address?

Use the following syntax (the -d options deletes the rule from table):
# iptables -D INPUT -s xx.xxx.xx.xx -j DROP
# iptables -D INPUT -s 65.55.44.100 -j DROP
# service iptables save

Copy and paste text with vi or vim

The ability to duplicate text in an editor can be handy. vi and vim have several useful copy and paste commands.

The command ‘Y’ or ‘yy’ copies (yanks) one or more lines. To copy one line, two lines, 10 lines, and all lines to the end of the file, respectively:

Y 2Y
10Y
yG

To paste the text contained in the buffer above (uppercase P) or below the current cursor position (lowercase p), respectively:

P p

It is also possible to yank text within a line. The following commands yank text from the current cursor position to the end of the word and the end of the line, respectively:

yw y$


The same commands paste the text within a line. Lower case p pastes after the cursor position and upper case P pastes before.

Paste will also work with deleted text, either lines or parts of lines. Be careful not to execute any other commands prior to pasting as this will empty the buffer.

How to mount the red hat linux iso files

If you want to mount the Red Hat ISO files (in order, for example, to
view their content), you should use the following command:

mount -r -t iso9660 -o loop -v  

Replace  with the full path & name of your ISO file and
 with a mount point (e.g., '/mnt/iso').

Adding VNC Server to Red Hat Enterprise Linux 6.x

In many Linux distributions, a VNC server is installed by default, but with Red Hat Enterprise Linux 6.x the package must be manually added.

Note: Although the test system for this blog was a RHEL 6.3 system, these steps should work with any RHEL 6.0 or CentOS 6.0 and above Linux system.
First, locate and mount your RHEL 6.3 install media.

[root@localhost ~]# cd "/media/RHEL_6.3 x86_64 Disc 1/Packages"
[root@localhost Packages]# pwd
/media/RHEL_6.3 x86_64 Disc 1/Packages

Next load the RPMs to support the VNC server with the following command:

rpm -ivh xorg-x11-fonts-misc-7.2-9.1.el6.noarch.rpm \
tigervnc-server-1.0.90-0.17.20110314svn4359.el6.x86_64.rpm

If you did a manual install you might find you need additional packages.

[root@localhost Packages]# rpm -ivh xorg-x11-fonts-misc-7.2-9.1.el6.noarch.rpm \
> tigervnc-server-1.0.90-0.17.20110314svn4359.el6.x86_64.rpm
warning: xorg-x11-fonts-misc-7.2-9.1.el6.noarch.rpm: Header V3 RSA/SHA256 Signature, key ID fd431d51: NOKEY
Preparing...                ########################################### [100%]
   1:xorg-x11-fonts-misc    ########################################### [ 50%]
   2:tigervnc-server        ########################################### [100%]

  Before we can start our VNC server, we need to edit the configuration file. The file is located in /etc/sysconfig/vncservers.
In my example I am going to add remote desktop capabilities to my Oracle user id. I am going to set this up with a remote desktop size of 800×600.
To achieve this I am going to add the following:

VNCSERVERS="1:oracle"
VNCSERVERARGS[1]="-geometry 800x600"

The first line adds a new VNC listener for the oracle user on port 5901. The second line sets the resolution to 800×600.
You can add additional users to your configuration file. If we wanted to add the user gruffdba to the configuration, it would look like this:

VNCSERVERS="1:oracle 2:gruffdba"
VNCSERVERARGS[1]="-geometry 800x600"
VNCSERVERARGS[2]="-geometry 800x600"

 
Next, we need to set a remote password for users. To do this, log in as the users you added to the VNC server configuration file and use the vncpasswd program to set the password.

[root@localhost Packages]# su - oracle
[oracle@localhost ~]$ vncpasswd
Password:
Verify:
[oracle@localhost ~]$

 
Now let’s set the VNC service to auto-start on boot, and actually start the service.

[root@localhost ~]# chkconfig vncserver on
[root@localhost ~]# service vncserver start
Starting VNC server: 1:oracle 
New 'localhost.localdomain:1 (oracle)' desktop is localhost.localdomain:1

Starting applications specified in /home/oracle/.vnc/xstartup
Log file is /home/oracle/.vnc/localhost.localdomain:1.log

[  OK  ]

Okay, we have an operational VNC server, and you can now connect to your Linux server remotely with a VNC Viewer.
If you completely disabled your firewall, you should now be good to go. If however you cannot connect, it might be that you have a firewall blocking you.
We need to allow connections on port 5901 through the Linux firewall. If you added two users to your VNC server configuration file you will need to open up port 5902 as well. Each additional user added gets the next port number, but in my example I only added one.
The command to add the port to the allow-list is as follows:

iptables -I INPUT -m state --state NEW -p tcp --destination-port 5901 -j ACCEPT

If you are having problems, try this and then see if you can connect. You will need to be root to execute the command.
The firewall exception we just added does NOT persist through reboots. In order to make the change permanent, use the following:

[root@localhost ~]# /sbin/service iptables save
iptables: Saving firewall rules to /etc/sysconfig/iptables: [  OK  ]

  You can check what firewall rules you have as follows:

[root@localhost ~]# iptables-save
# Generated by iptables-save v1.4.7 on Tue Mar 26 17:51:12 2013
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [4:608]
-A INPUT -p tcp -m state --state NEW -m tcp --dport 5901 -j ACCEPT 
-A INPUT -p tcp -m state --state NEW -m tcp --dport 1158 -j ACCEPT 
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT 
-A INPUT -p icmp -j ACCEPT 
-A INPUT -i lo -j ACCEPT 
-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT 
-A INPUT -j REJECT --reject-with icmp-host-prohibited 
-A FORWARD -j REJECT --reject-with icmp-host-prohibited 
COMMIT
# Completed on Tue Mar 26 17:51:12 2013

Now let’s try connecting to our Linux desktop from my Windows laptop using VNC Viewer. Enter the password you set earlier and you should see your Linux desktop:

Remove files older than 7 days - Linux

The Linux find command has several different uses. One of these uses is to remove files that are older than x amount of days.
This particularly useful when we want to clear down trace files that have been building up over time. To do this we can access to the oracle bdump directory, then execute the following command line code:

$ find *.trc -mtime +7 -exec rm {} \;

The above code will remove all trace files in the current directory that are older than 7 days.

Code breakdown

find -mtime + -exec \;

Find – finds the files specified by the filename
-mtime + – days older than current system date
-exec – command to execute with found files

Further reading

It is possible to execute different commands upon found files, however this is outside the scope of this post. For more information on the find command please see the find man pages: Find Man Page