Unkown File ~

I support a small office network of machines running W.98 and a couple of laptops running XP. I keep having a file named ” ~ ” appear on the desktop of one of these machines and it recently appeared on one of the laptops too. This file is 197 KB in size.

We are running Norton Antivirus and the virus signatures are updated weekly. Norton doesn’t identify this file as a virus. But if I delete it it returns within a couple of days. We use a dialup ISP and do a lot of email. Can someone tell me what this file is and where it originates from and how do I get rid of it permanently.

Thanks
Don