That model dates back to the Windows XP era and only has 1GB RAM which is non-upgradeable so you cannot increase the RAM to 4GB.
Because of that, and other limitations like the non-upgradeable Intel Atom CPU, there's only integrated graphics etc., there is no way you can put another GPU, and Windows 8 would be exceedingly slow.
You can't run 64-bit Windows on it, because the Intel Atom N280 is not 64-bit capable.
Last, but not least, there would be a big drivers problem because Sony hasn't ever released any Windows 8/8.1 drivers for it.
So I'm afraid what you were wanting to do with it just isn't possible.
If you want better performance it's time to retire that laptop and get something better.