Windows 98SE possible upgradation to the higher windows version

Dear all,

I have a probelm with my windows 98se operating system.Mine is a compaq
1200 series presario and I have winodws 98se installed into it.I need
to install a new antivirus software which I don't have one,But the
latest version of antivirus software is not compatible with the Windows
98.I either have to find a free antivirus software that is still
compatible with the Windows 98 SE or I would like to go for an
upgradation possibly with win2000 or higher to download the lastest
antiviurs software..let me know the possibility?..

can you give me a link of the antivirus software that works well with
WIN98?

How can I upgrade my WIn98 to new version WIN 2000 or higher?.How can I
back up the important files of the WIN98 SE ?

Please Let me know~!
/
VSV