Great comments thread about what software to Load up [on] your USB drive before you visit your parents for Thanksgiving. And just in general, a good list of software to keep in mind when you have to clean a PC.

I have Macs both at home and at work, but my husband uses a PC, and I also have a PC on my desktop at work for checking websites, and they've both gotten viruses and spyware/adware that had to be cleaned off. It's not just clueless parents that install these things, some of them are very insidious.