Upgrading cpu for satellite a135-s4467

I bought this laptop over 2 years ago and since then I've downgraded to XP because Vista is just too slow on this thing. I've upgraded to 3GB of memory, partitioned space so try to help things, but still seems to run low. One problem I think I may have is the fan needs replacing, which I have ordered one, but I don't think that could be the reason for Vista running slow. I want to switch back to Vista because I lose my battery management apps in XP so my battery only lasts an hour and a half or so when in Vista with management, I could get 3+ hours.

I currently have the intel centrino core 2 duo t5200 and have been looking into the t7n00's, but have seen things with socket type and memory and stuff and want to make sure I get something that will work with it.

Anyone tried to upgrade the processor in one of these and know what is compatible and if it will help at all?

 

If you want a T7x00 series you can but you have to get one of these 3. You can only use these 3 all other t7x00 chips are socket P. Your laptop is socket M because the t5200 is only made in socket M.

CPU l2 cache speed
T7200 4mb 2.00ghz
T7400 4mb 2.16ghz
T7600 4mb 2.33ghz

 

That's what I thought once I did enough research. the 800 mhz used different memory types and the t7700 I knew had the different sock type.

Any idea if it'll help my performance at all? I found a new t7200 for just $100 and figured, since I'm not going to buy a new laptop anytime soon and I like this one, it would be worth it if I can use vista again. My dad got a desktop last weekend and it has a 2.3 ghz and he said it is wonderful with vista and running his stuff, but I can't find one of those for a reasonable price.