XP Problems - Freezing, Programs not responding, etc. - Please help!

[BustaRomeo]

I just set up a wireless network to my month old computer so naturally for the whole day I've been on the net. I installed a program (some mp3 dancer thing) and along with it came superbar. Superbar is apparently quite a pest, so i went about my way to remove it's files and registry values. This influenced me to download and install adware 6 and pest patrol. i found a few things, and i went on a mad frenzy of removing files and registry files. after a while I realised that my wireless connection was no longer working. It was saying something about error 0. I restarted my computer, and THIS is where ALL the mess started. First of all, my startup sound doesn't play. Secondly, all the programs that usually run in the taskbar thingy at the bottom right are no longer there, only n-view is running. Thirdly, if i try running certain programs (windows help, network connections, etc.) my computer refuses to open them. If I try doing ANYTHING (even getting ctrl+alt+del to do it's thing) it waits like 2 minutes before it opens (after which my startup sound plays). If i look at the processes in the task manager, none of the programs that are running have users' names next to them. Please help me! I don't know what's wrong or how to fix it, please help!

[Confused]

Try picking a restore point prior to the download. Start > Help and Support, click on Undo changes to your computer with system restore.
Chas