Windows won't load properly?

Hey everyone, I'm sure this question is asked a bunch of times but I'm not entirely sure what is causing my problem so I can't look up anything specifically.

Last night while on my computer my McAfee virus scan created a pop up saying it had detected a trojan and needed me to restart in order to remove it. I'm usually suspicious of any pop ups but I know McAfee has real-time scanning and the pop up matched my current version's template so I decided to click "Restart Computer".

Well it may have been a mistake because as my computer rebooted it entered the "Boot in Safe Mode/Normally/Last Known Good Configuration" screen. When I select "Start up in Last Known Configuration" the Windows Xp Home Edition "load bar" pops up then I hear a slight "click" in my computer and it simple restarts and goes back to the "Boot up in Safe Mode/etc" screen.

I AM able to boot up in safe mode however, and while in safe mode I've used both Malware Bytes and McAfee to scan and have cleared up everything but I still get the problem. I've disabled all start up and system services while in boot mode as well as using the original boot.ini file but it still refuses to start up normally. For some reason there is also no system restore point available for me to reset back to. Can anyone help me out? I bought the computer open box from Best Buy about 5 years ago and it did not come with a Windows CD. Thanks.