My computer wont let me open anything when i download an antivirus?

Try running rkill. READ THE DESCRIPTION. it is a small executable, no need to install. If rkill shuts down anything other than itself, you are infected, but can now install, and update your AV. http://www.bleepingcomputer.com/download/anti-virus/rkill If you are infected, you will also want to get MBAM, and run a full scan with it, it is a must for malware removal. http://download.cnet.com/Malwarebytes-Anti-Malware/3000-8022_4-10804572.html?tag=rb_content;main If rkill does not shut anything down, I'm not sure what could be wrong, does it only do this when you download an AV?

what antivirus did you get? maybe it was a scam or a fake. my advice would be to download AVG free antivirus or avast (also free) or microsoft security essentials (also free if you have a legal copy of windows) on someone else's computer and have them burn it to a disc for you and you can try to install it on your computer from the disc.

Try this: Firstly, boot your computer to the Safe Mode menu screen. You do this by repeatedly pressing F8 as soon as you boot up. Once there, use the arrow keys to highlight Safe Mode with Networking. Continue to boot from there, by pressing Enter. If that's successful, download and run TDSSKiller.exe from Kaspersky Lab. It's tiny, and takes just a minute to run. It hunts down and kills a specific family of rootkits. Here's a link: http://support.kaspersky.com/faq/?qid=208280684 Regardless of the results, download the free version of Malwarebytes' Anti-Malware (MBAM). Install it, get updates and run a full scan (still in Safe Mode). Here's a link: http://www.filehippo.com/download_malwarebytes_anti_malware/ After that, boot normally and run another full scan with MBAM. It will detect any malware that wasn’t running in Safe Mode. You should now delete TDSSKiller.exe, as updated versions are often made available. Malwarebytes' Anti-Malware can be easily uninstalled, should you wish to do so, but it may prove to be beneficial in the future. Hope this helps.

the anti-virus is probably trying to prevent you from getting any viruses but it really is doing its job to well or it might be that you already have a virus and they are just interacting. the best anti-virus that is free is malwarebytes, or microsoft security essentials.(they work great together). the best paid anti virus is norton