I have successfully installed Windows XP Pro on my Dell mini 12 which has a slow processor (Atom) and a non-upgradeable RAM (1 gig max). BTW, my laptop was pre-installed with a Vista OS and it crawled literally (it was sluggish to say the least) on some applications. Hence, the downgrade in the OS.

My XP now runs smoothly. I wanted to have the applications (2 encyclopedias- Encarta 2009 and Britannica 2009) on my netbook run faster. Then I came across Eboostr on the net. Its technology is similar to that of Readyboost in Vista but quite more powerful. Moreover, I used my entire 8Gig USB to act like a RAM and it work quite well for me.

BTW, prior to downgrading to Windows XP, with the Vista on my mini 12, I also tried readyboost. But sad to say, there was no visible difference between having readyboost or none. Besides, readyboost is limited only to 4gig on my 8gig USB...