On custom made computers, you should have saved the operating system installation disc, a CD with all the drivers, a disc which contains all the secondary programs you've installed on the computer, plus a disc with all your important pictures, files, music, etc...
If you don't perform all these steps, then there is still a possibility that the machine could be controlled by someone else. Malware on the machine is the primary reason you can't update your antivirus, etc....
Yes, you could follow the steps below to attempt a cleanup but the steps below are just a beginning... Once cleanup has occurred using these steps, then you'll need to run other antivirus programs, check your email, firewalls, routers, and all other devices, just to make sure you don't have any remnants of the malware remaining. It's and extremely drawn-out task and in the long run, reformatting and reinstalling everything is quicker and safer.. So....if you want to give it a try, follow these steps.
If you can download the tools listed below on the problem computer, great, but you may need to use a separate, clean computer, download the tools, copy them to a DIFFERENT flash drive or CD, then transfer them to the infected computer.
Once that's done, then restart the computer into "Safe Mode with Networking" and use the instructions below. If you can't start in Safe Mode, then run all the tools while in "normal" Windows first, then run them in Safe Mode afterward.:
After downloading or transferring it to the problem machine, run the
following tool to help allow the removal programs below to run.
(courtesy of Grinler at BleepingComputer.com)There are 3 different
versions. If one of them won't run then try to run the other one. Be
patient.... as a black window should open, then close after finding all
the background programs.Vista and Win7 users need to right click and choose Run as AdminYou only need to get one of them to run, not all of them.
IMMEDIATELY after running the "Rkill" tool above, run/install the Malwarebytes and
SuperAntispyware installer and update files from the links below which
you've also copied to a CD or flash drive, and transfered to the problem
machine. Do NOT restart the computer after running Rkill. After that, run a full system scan
and delete anything it finds.
Malwarebytes Installer Download Link (Clicking on the links below will immediately start the download dialogue window.)
Next, install and run a full system scan with the SuperAntispyware program
and the manual updater from the links below. As before, you may need to
rename the installer file to get the program to install.:
And after that, if everything's fine by you can't connect to the internet,
then follow the procedures below to check your network "proxy" settings
again.Open Internet Explorer and go to Tools-Internet
Options-Connection Tab. Click on the LAN settings button. IF there is a
check mark next to "Use a proxy server for your LAN", uncheck it. Click
OK. Then OK, again.
And finally, download and run the tool below to bring back any files that may have been hidden by the malware on the computer.
Hope this helps.