Problems with macbook

Hey all, first time here!

My macbook has been acting strangely lately.
First of all, it wont go to sleep without closing the lid. When i put it on sleep, it wakes up right after. Also, it seems to be running hot. Windowserver sometimes spikes to 20% of processor usage. I am not having the performances with this computer that I had before

It's a white macbook running snow leopard

2.4ghz core duo and 3gb ram

Help is appreciated! thank you!

 

Thank you, it fixed the sleep problem, but windowserver is still acting up!