How can i make my computer fast?

Hello,
How can i make my computer faster? i Have kaspersky antivirus 2010 full version. I also tried all 4 uniblue products and i have 640 mb ram 64 mb graphics card and 2.00 ghz. my operating system is xp 2008 full version.
I also tried many softwares which could make my computer faster. And also my internet speed is super slow.It only gives 3.5 or 4 kbps download rate and upload rate is only 0.5 kbps. please can you help me.I don't have enough money to buy a new pc. Anyone please help me!!!!!!!!!!!!!!!!!!!!!!!!!!! but before it worked like having 4 gb ram. It was very fast before and moving and pasting takes too much time. the start up takes 5 minutes to start and the welcome screen goes after 10 seconds and the programs come after 5 minutes.again please anyone help me.