Hmm, it sounds like you might have a Trojan horse or a malware infection issue.
Before your pc went downhill did, avg or spybot or anything else report virus like activity ?
If either one of them picked up something it would have told you the virus name or propable cause of the problems.
Since you also said your CD/DVD rom drive is now currently offline I am guessing that something happen to the drivers for it get corrupted and go offline.
Thats is probably why you got the blue screen of death and something else might be gone as well.
For starters we need you to download MSSENTIALS and Malware bytes free editon, have windows disbale system restore and reboot.
Start up in safe mode by pressing F8 and try to uninstall AVG first and spybot SD>
If you can get that going and done, install malware bytes first on normal startup.
Once installed have it fully scan your pc, if it picks up anything it will ask for new definetions if it can not elminate a new threat.
Also after the reboot and infection delete attempt by malware if it fails, install mssentials that you can download from another pc.
Have MSSENTIALS scan for any problems, or if upon starting up the antivirus it may do this automatically and pick up a trojan or anything else like that.
Keep in mind even microsoft's antivirus can't stop everything in it's tracks especially when it's too dangerous and trying to take down windows core files directly.
However you'll have the advantage just a little bit and might destroy the problem or help windows get back into decent working order.
Please tell us what kind of cd-rom you have, if you don't know take it out and read the lable on top of the drive and tell us what you got.