On ebay you can buy Windows XP for £35. Windows XP has support (for microsoft patches) until 2014 and probably also for virus scanner.
You can also shift to a non MS operating system like Linux,*BSD etc. which not really need a virus scanner.
Hi...
This really depends on system specs and the subsequent abililty of the system to handle these OS's. Many systems designed for Windows 98 back in the late 90's using the original hardware would most likely not be able to handle XP well, if at all, without upgrading or replacing the system.
@nightshade: If purchasing a copy of Windows XP is a possible consideration in the future, I would recommend getting a "full retail copy,"
not OEM. Here is a listing on
ebay for both the Home and Professional version. You can also find copies at other online stores like
Royal Discount. However, as I have mentioned above, make sure your hardware can handle the increased resource requirements.
Feel free, if you would like, to post your hardware specs or "make and model" and we can give you an idea of what you might need to do.
May God Bless you!