Er, Bro, TX57 using solo core processor with 1.33Ghz speed only, what you expect ? To enhance the speed, what you can do is just upgrade the RAM. But do take note, the max Ram you can actually go is 1.5gb Ram. Thanks =) 
Err, to downgrade your TX57 to window XP at cost, is impossible to do so. Unless you have the Window XP professional SP2 installation CD. Then, go to this website -- >
http://www.sony-asia.com/support/download/...site=hp_en_AP_i
Download the Window XP downgrade drivers which will takes you around 1 day +, after that downgrade yourself.

Or lets say you want someone to help you, just download the drivers everything and saved it inside your pendrive, after that bring ur pendrive + your laptop + Window XP installation CD, ask Sony Style staff to help you at no cost.
If you back to those Sony centre which owned by dealers, confirmed will have some charges on it. By the way, Good luck, coz i do the downgrade for TZ series before, took a loooooooooooooooong time. 

Attacusatlas,
FYI, your RAM from S46 can be used in TX57 since both are using DDR2 RAM. It's compatible.
But, do remember, TX57 only got one slot available for the RAM itself. You cant take out ur S46 RAM to put into your TX.
Now inside your TX57 laptop adi got 512mb memory + your additional 512mb RAM, so your laptop already have 1GB ram.
So in this case, inorder to become 1.5GB RAM,  you need to purchase another 1GB DDR2 RAM to slot in, inorder to get 1.5GB RAM for your laptop.
The extra 513mb u just keep it bah.

Yea, T series mostly for longer battery life and the performance wise is not that great if were to compared with S series since S series always the top of the range laptop in VAIO.

Hi there, when you use recovery CD, it will restore/format back your HD back to factory setting. Of course its free from malware or virus, but you arent free from "bloatware". bloatware here means any unnecessary program running on the background. easy to settle by disable in msconfig or uninstall them .