Remotely accessing Windows XP desktops

Why Remote Access?

These days remote desktop access is a fundamental tool of trade for IT support professionals. There are a myriad of options too. You can use the Windows Remote Desktop Protocol built into Windows XP, Server 2003 and later versions. You can install a third party software solution, such as VNC (which includes many free derivatives, or a web based solution like LogMeIn.

In most cases, some forward thinking is required. You need to have the software installed before you get the urgent call from the customer requiring either a quick 5 minute remote access session, or a 60 minute drive across town.

LogMeIn does allow "on the spot" installation without preinstallation, however some level of user expertise is required, and in cases where the PC is unattended, this isn't an option.

For Windows XP machines, a logical choice is the built in Remote Desktop system, however the default windows installation settings leave this disabled, and the windows firewall blocks access to the port even if remote desktop is running.

But luckily there is a way to turn off the firewall and enable remote desktop without having to sit at the PC. All you need is authenticated network access. This means either a password for a local administrator account, or if the PC is a member of an Active Directory domain, a domain admin account.

How to enable Remote Desktop

Enabling remote desktop is accomplished using the REGEDIT program. Editing the windows registry can cause SERIOUS PROBLEMS so be aware and exercise caution.

To start regedit:

START / RUN / regedit

To connect to the remote PC, select FILE / Connect Network Registry

The key you need to edit is

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server

Edit the fDenyTSConnections key to be 0

Close the registry editor.

How to disable Windows Firewall

Enabling remote desktop is no good if the default Windows firewall settings are still blocking access.

To modify the windows firewall requires the use of the PSTools suite available from Sysinternals.

Once extracted, the tool to be used in this case is psexec. psexec allows you to remotely execute a program. In this instance the program we want to execute is netsh which allows control of the network subsystem, including the firewall.

To execute netsh on the remote systemm execute the following command:

psexec \\ netsh


Where is the name of the remote system.
Once you see the netsh> prompt type in the following:
firewall set opmode disable

WARNING

This method actually disables the windows firewall, which reduces the security level of the PC in question. If the firewall is required, please enable the firewall again afterward.

Another option is to modify the firewall to allow the RDP protocol.
In this case the command would be:

firewall set portopening TCP 3389 RDP


Once finished, type EXIT to close netsh and psexec.

To commence your remote desktop connection you can use the following command line:

mstsc /v:


All things being well, you should now be able to connect remotely and keep your client happy.