My PC crashed a few weeks ago, kept showing the BSoD as explained here: http://www.bleepingcomputer.com/forums/t/323469/bsod-error-0x00000073/
but that's now fixed. I cleaned my PC out, leaving it only with the most basic software. When I tried installing CCleaner and ATF Cleaner from the setup files I downloaded a few months ago neither worked. They worked perfectly before the crash. CCleaner would open for a second or two before automatically shutting down; I checked the folder in Program Files (C: drive), and a lot of files were missing, even if I re-installed it. ATF Cleaner wouldn't even open.
When I tried to check with an anti-virus software, I realised I had removed it as well, so I installed an old version of Symantec Antivirus I had from before. It went crazy on me and every time I right-clicked or pressed 'Delete' an installation screen would pop up. I deleted its folder from the C: drive, and it seems to be almost fully gone.
Installing a software like WM Converter worked the first time, but then it kept saying it's corrupted and won't open. Other software like Trojan Remover and HijackThis seems to be working fine.
So... what do I do? I don't have any anti-virus software installed at the moment; which one do you recommend I use?