Yahoo toolbar was installed on workstaions on our LAN. After uninstalling the program I find that windows registry was modified and client downloads are blocked. How do I reset registry?

I was trying out McCafee Anti-Virus software, but saw BT Yahoo free software by Computer Associates, I removed the McCafee Virus software and tried to load your CA software but nothing happens! (The anti spy works & Mail Protection) I have clean my registry with PC tools and restarted my PC a number of times I have downloaded the Software form the site Numerous times But the soft ware still says "Install now" I would be most pleased to here what I am doing wrong? Just to inform you I have worked with computers for over twenty years. Therefore, I’m not a novice; you don’t have to be gentle with me. I have Zone alarms firewall install and am running XP pro (Pack 2)

So today I was trying to go on to Yahoo!Answers and my computer starts to go slow. So then I took like 10-20 minutes for it to get to the screen so is there any tips for my computer to speed up, without paying for it?

Not only that, I need Virus Protection, anti spy, and firewall. I've been using the suite that is included with ATT Yahoo DSL but I need a different one because I purchased a new computer with Vista and they dont support Vista (and won't until at least August). Preinstalled on my computer I have a free trial of Norton but I was not happy with them on my last computer because I felt they take up too much memory. Give me some suggestions and why. I need the works but they don't have to be from the same provider. I was leaning toward computer associates but tell me what you think.

My computer is infected with a virus or something of the sort. The virus is popping up on my desktop, saying I need to download this certain virus protection, which is actually fake. The problem is the virus is blocking any searches, websites, or anything that has to do with virus/malware removal. Yahoo is really the only place I can get onto that has some answers about removing this. Please, do all you can to help. Obviously you can't provide me with links to something, unless you tinyurl them (maybe).