Tuf's option is certainly worth a try.
But if that fails, just have a look at the RPC Service.
You can get to the Services Console by going to Start > Run, type in services.msc and click OK. When the console opens, scroll down and look for Remote Procedure Call (RPC). You may have to drag the "Name" column header divider to the right to see the whole name, and 'do not' get the entry confused with the one below, Remote Procedure Call (RPC) Locator.
If the Services Console does not list any entries, then that is a sign that RPC has been disabled. In which case you would have to edit the registry as stated in the Microsoft link given above.
Remote Procedure Control (RPC) should be set to "Manual" if your XP is below SP2, or "Automatic" if your XP is SP2 or above. You can change the setting by double clicking the entry, and then in the "Startup type:" select (Manual/Automatic). If you want to start it straight away, click Start if the button is available.