Your first problem sounds like a failing harddrive. Your 2nd sounds like spyware. If I were you, I'd reload the system. Format the harddrive and see if you find any bad sectors. There are ways to sometimes fix these, if you get them, but it can be a pain and might be a good idea to just get a new harddrive then reload the software on this. That SHOULD fix your problems...
Desktop: Athlon 64 3700, 1024M RAM, GF 6200 TC 256M, 2x 80G, 2x DVD-RW
Laptop: Sempron 2800, 512M RAM, Unichrome, 60G, DVD-RW
Macintosh:G4 1.33GHz, 512M RAM, Radeon 9200 32M, 40G, DVD/CDRW
They get me from 0 to 1...