I installed the crap moosoft and even it said my PC was clean. Your server scanner is crap.

I attached the moosoft results. Seems like nothing more then a gimic to get people to buy their product because undernet is partnered with them.

I'd like to point out that a web interface virus scanner cannot properly find all virus' on your computer.

As for the "Your PC is infected" messages, it is possible another infected PC has been connecting to undernet via the same IP address you are connecting with, this can be because there is a problem with your router, or there are multiple computers behind the same router (including yours), your ISP could be doing some kind of IP address sharing between multiple customers (basically multiple computers behind same router including yours trick).

So if your PC truely isn't infected, start looking outside of your PC for the cause of the problem.

If you are certain your pc is not infected, the best solution would be to email abuse@undernet.org and include the nick!user@host and realname that you are using to connect along with the entire gline message.