External backup gone wrong

By disappearing I mean I had no start button , I couldn't do anything all functions were gone. so I just shut it off. But during the process I was told that the files will be replaced and I may have clicked onto yes instead of no, and proceeded with the backup.
when the desktop does not appear, then press crtl+alt+del together to bring up task manager, then in file/new/ type in explorer.exe and your desktop will come back. Sometimes depending on what is going on in the background the desktop will be slow to appear, so I have to see what is running and cancel it.

you need to run chkdsk with the /r parameter either from the recovery console or from the command prompt, you should do this whenever there has been an ungraceful shutdown.
Problem solved thanks for your help elizabeth23. I have another question for u. I tried to download a program to do the backup and i got a message that said seagate toolkit.exe in not a valid Win32 application. How can i fix this.
I think when yo get .exe in not a valid Win32 application that means it dont work with XP. Elizabeth23 would know better then me..