application error

I am running Windows XP with Service Pack 2. I am getting a popup message sometimes that states "Application Error - userInit.exe" and then "The instruction at "0x7c901010" reference memory at "0x052f273C. The memory cannot be read. Click on OK to terminate the program." This sometimes changes from time to time. Also msn_sl.exe and Iexplorer.exe and some others are at fault. It looks to me that the "0x7c901010" error is always the same but the second changes from time to time. Can anyone please help me how to solve this issue? Thanks

It could be that the users Are Automatically Logged Off When Attempting to Log on to Terminal Services. So to resolve this behavior, the administrator must give the user the right to bypass traverse checking. For more information, check this link - http://support.microsoft.com/kb/272142

thanks for all the trouble but i cant access things like add remove, internet options or things like that? when i try to it comes up with rundll32.exe application error (failed to intialize properly (oxc0000005)?

and when i start windows it logs on into where its jst about to load desktop then the error pops up userinit.exe error

sorry again and thank you heaps