How do I give authority of the cpmputer to the internet?

[WW]

I am always having a problem with my computer locking up and IE stops responding with windows or the other way around. I want this to stop. i am running windows vista, trash os. I want to give the internet the authority to take whatever resources it needs to run on this computer without locking me out or locking up. Vista tries to block the internet and i have to give permission to allow everything on here. I want it to stop. I have a window xp disc. Can I uninstall vista and go to xp? If so will this stop the locking up. It locks up every 15 seconds for about 30 seconds and then locks up again in 15 seconds. This happens over and over and over again. Please help and tell me if throwing this computer out the window is what I need to do. I am running vista home, service pack 2, 288 gb harddrive, 2 gb ram, AMD Athlon 5200+ 2.60 ghz processor, 32 bit os,

[Fred]

First download the free scanner from http://malwarebytes.org and run the full scan. It may be a virus infection. Then make sure you have updates turned on and run as many updates as you can. also right click the C: drive in Computer, and select properties, then tools and disk check. Tell it to run and select BOTH tick boxes. When it complains about needing to restart, do so. Do NOT interrupt it however long it takes.