Where can I find an online anti-virus that doesn't install on your PC?

[collenbernardini59135]

I've got 5 PCs that I'm trying to use to train disadvantaged young
people. The problem is they are riddled with viruses and a firewall
blocks me from updating them. The people in charge of maintaining the
PCs won't fix them or give me the admin password (Win XP) to let me
install a new or updated antivirus the centre is being shut down in a
few months.

If they were working, I could still do a lot with them, so I've been
looking for a good online virus scan - but they all try to download a
little .exe onto your PC first, and the settings on the PCs won't
allow that.

Suggestions? Solutions? Links?

[Eugene Trotsan]

You could install a linux distro side by side with Windows and dual boot
it when you need to.
Otherwise you are looking to resolve the issue personally with the
admins. And by the way, don't let them catch you modifying the hard
drive or they will get upset! ;)

Regards,