In earlier versions of Windows (3 and 3.11), PIF files where used to configure DOS applications that had to be run under Windows (memory and display configs, etc.).

I can't remember if these files were also necessary under Windows98. Maybe...

If this is the case, you may have to adjust the memory settings (DMA and other options) by editing the file.

It can also be something totally else than what I'm telling here about. In that case, sorry.