pc only starts in "F1" half the time it ignores my commands..

About 3 days ago my pc didn't shut down so I pulled the plug .Since then its been acting up ,I pulled the plug before with no bad results.Now it doesn't always load my settings ,just goes black .other times it shows my desk top less the icons. I have a XP disk but my cd drive isnt working.It doesnt even show up in my directory. when I click on favorites sometimes instead of showing me all that I book marked ,it asks if I want to add the page I'm on to favorites. Yesterday I cleaned it with Malware bytes antimalware ,and then super anti spyware ,so I dont think I have a virus or anything.My pc is legit and I have the registration numbers microsoft gives .Can I download windows xp ( like what I have ) and re-do the whole thing? Or is there some way to fix it with out doing all thaty? .
Neil

Please visit this webpage for a tutorial on downloading and running ComboFix:

http://www.bleepingcomputer.com/combofix/how-to-use-combofix

See the area: Using ComboFix, and when done, post the log back here.

I already had combofix from several months ago whenyou rescued me, but it said error when I tried to run it I deleted it and downloaded the one from bleeping cpmputers and its saying the same thing. As soon as I click on it to "run" a box apears saying error or corupt. This pc is kinda beat up ,the usb ports on the front are all busted up ,If you don't have a fairley easy fix I will not mind getting another pc,I buy em used for $100.00 or so. The only thing is they are all running windows XP and I hear its not taking updates from msn anymore .Would that matter much ,or is it even true?

It would be of much better advantage to buy a low cost PC from HP or Dell.

Here is a couple very good, low cost, PCs:

Dell Inspiron Zino HD

Dell Inspiron 560s

Compaq Presario Laptop


Other than that, what other diagnostics would you like to do on the current computer?