Strange Files Being Created

[ubigdummie]

 
I have just formatted my hard drive and reinstalled WinXP Pro. I now have files popping up in almost all of my directories, even on the desktop. The files all look like this...

_hash001156
_hash001008
_hash000884

The files all have _hash at the beginning and 6 numbers following that.  Has anyone come across this before? ANY help will be much appreciated.  Thanks.

[merlin]

run a virus scan ?if you can find these files delete them and get yourself a reg cleaner like advanced system optimizer/hth