Those things are total crap. I love people I know buying them though, because they generate revenue for me lol. I've worked on 3 in the last few months that belonged to people who hadn't had them long. In every case, the issue was rooted in their terrible OS installs. They are loaded with crapware, and they have XP running on a FAT32 file system. LOL!
The ones I have seen are running Vista. Were the ones you worked on purchased at Wal-Mart?