it will not let me post my computer problem

ok seriously every time i try to post what my problem is it times out and will not post it... but something stupid like this it will go through

Write it in paint, save it, upload it.

ignore please delete

Helps if you don't name your images swear words, but anyway, I got it.

You're going to need to get in safemode and hope it doesn't happen there, and see if Security Essentials will update there. If it won't, get a different AV and install it (Avira or Avast).

For one-off killing of viruses and malware I swear by McAfee Stinger. No install, just a standalone exe file.

Hijackthis, malwarebytes, removal of the reg key in safe mode, running every virus scan you can think of.

Malwarebytes can handle just about anything. You'll have to download it on another machine, viruses are known to redirect attempts to obtain it to a malicious download.

When I've been hijacked by fake security software I restart in safe mode under the same (using the same profile) and run Spybot Search and Destroy. I've also read good things about Malwarebytes but Spybot did the trick for me. If you restart in Safe Mode with Networking you may be able to download whatever you need. One thing that hinders internet connectivity is this type of malware can set your internet browser to connect by proxy. You'll have to disable that in your browser settings if that is the case.

Spybot is good, but it sounds like what you have is pretty nasty, so again I suggest the nuclear option and just go all out.

The nuclear option still needs to be approached correctly. If you want to save any of your data, the data can't just be copied off and copied back, or it can carry the infection to the new install.

My experience with these things is that they look tons worse than they are. I was getting mentally prepared to wipe my stuff when I solved the problem relatively easily. I've had about 3 rounds with this kind of stuff and in the end they have all been easy to defeat. Of course a reformat can be good but there is always some data that you would like to recover, as JM points out, so you need to be careful. But, also from my experience, these things don't actually infect your files. They just make it look like they're all infected. I basically follow up my repairs with CCleaner now.

Boot from a Linux LiveCD, make sure the NTFS-3g package is installed, fine a good av scanner (not sure what exists for linux, clamav is good AFAIK) and then mount your drives and scan it all.

Last resort you should be able to reinstall Windows without formatting, but then be careful, I would recommend reinstalling all apps instead of using any programs left over from the old install, and make sure to run an AV scan before doing anything else.