Has all data been lost?

A friend of mine was receiving error codes (???) in Windows 2000 and shut the machine down. She was unable to boot back up and has since restarted with the Windows 2000 disc. I am not sure, but she believes she re-installed the OS. She says that this only took 1 – 5 minutes. However, now she can’t see her documents and fears they are lost. They were not stored in the “my documents” folder, so I am wondering if they might still be on the HD. Any thoughts?