Sony Vaio Desktop System Restores

Can I sell my desktop?

I bought a Sony Vaio desktop in March 2006 … great computer, runs too. It has Pentium 4 and Windows XP, 17 flat screen. " I just got a great laptop and I do not know what I should do with this "old" computer! is unrealistic to clean it and sell it? It's even worth it to ask for $ 100? I paid $ 1400 + for it, but I do not know if this is possible I do a "System Restore", or do I need do anything else (except clean the dust … not have used it in almost a year)? There really is not anyone in my family or friends who need a computer … so I'm not sure what to do with it? I could think of some things to do with a little extra money away!

I take that flat screen.