I've organized my post in a block format listing my computer information, issue, and how I've tried to fix it in an effort to make it easier to read. Thank you in advanced for any help you offer.
OS: Windows 7 Ultimate 64-bit.
Problem: I'm having issues getting my computer to start up in normal mode. It almost always freezies up during the start up phase. But it does so at different times. Half the time the computer will power on but the monitor remains completly blank. Somewhat less frequently, the computer will show the Bios information but stop before it gets to the Windows logo. JOther times the computer will freeze once the Windows logo shows up. And if I'm lucky enough to get to the desktop, the computer will freeze while loading the shortcuts.
What I've done: I've suspected that I got a virus because it didn't start behaving this way until right after I made a download and I found my Avast antivirus disasbled and unable to be reinstalled fresh. So I ran RogueKiller, adwcleaner, Malwarebytes, ESET online scanner, and a fresh install of AVG antivirus per advice I've seen other people get on these forums and elsewhere. Everything except AVG said they found something. I instructed them to delete the questionable files. But if anything the computer started having more problems starting up afterwards. I've also tried running the Chkdsk /r utility but it always freezes in the process.
If you need more information let me know and i'll provide it as quickly as I can. Again thank you for any help you can give.