I would advise that you get either the certificate from the vendor / previous owner, if you really can't find it with the manual or so, or get some cheap legal copy from ebay..
I don't know if without this you will be able to RE_install Windows; and finding that out after FORMATTING would be a bit too late.., so I'd wait a bit with fdisk & format
some Win95 systems come with a restore utility, that reverts the PC to the state it was in when sold. This might be started with a DOS-Bootdisk (see e.g.
www.bootdisk.com ) and might be called:
ERU or
recovery or ....
try googling and browse the microsoft knowledge-base
you could also try
- avast for DOS (see board-search)
- F-PROT for DOS
- CLRAV.com
the latter two you should find via Google or the link "VirusRemoval" below in my sig
you additionally need a clean, write-protected bootdisk for this, which has to be made on a Clean PC, of course..
be sure to select REPAIR / DISINFECT first, when viruses are found; only in cases where this is not possible, select rename or move