If you used windows XP ,try Lubuntu ,very little difference between the 2 ,well Lubuntu is 10 times faster and all the software is FREE and when Lubuntu updates it updates all software installed when windows just updates itself .Download the ISO of Lubuntu ,burn it to a CD/DVD and boot computer from it to try it out ,it will not install it unless you pick install
Distrowatch.com for all your Linux needs . Youtube also has TONS of reviews of all linux OS and it will also show you how to use if you get confused D’oh
I have it running well on a dog of an Atom processor Netbook with 1 gig of memory. YouTube would stutter on Windows Crippled (Starter). Smooth on Lubuntu.