Pavilion DV4 1465dx cannot boot past Windows 7 logo

[CaffeineTripp]

This is apparently a prevalent problem within the DV4 community with Windows Vista, upgrading the BIOS, and possibly something to do with an AVG system file.
I've downloaded the AVG Recovery file to a USB, booted into that and attempted a scan on the computer's hard drive and boot. Both seem to be fine. Renamed all AVG files, as instructed by AVG themselves, to .bak. This apparently helped the AVG problem among having a couple viruses and trojans (which I think is the major problem going on here).
Now I've com across one other problem trying a Safe Mode boot (in either straight Safe Mode, with networking, etc.), Windows will not boot after Classpnp.sys is reached on a Safe Mode boot.
Running a chkdsk will receive no errors to the hard drive.
Sometimes after sitting for a while on the Windows logo screen while booting a BSOD will appear very shortly and the computer will restart.
I am able to adjust the BIOS to boot from either the USB stick or the internal hard drive itself, but cannot boot from CD/DVD with a recovery CD of Windows 7 (which is installed on the computer currently) or any other recovery disc for that matter.
It's a friend's boyfriend's computer, so lord knows what's been done to it for the software or hardware.

Please note that the computer will not start up so I cannot run any scans from that particular computer.

[erico]

But you can remove the drive and put it in a USB external  enclosure.  Then you can scan it with an antivirus programwhen connected to another PC that has a decent AntiVirus/antimalware/antiadware program like ESET.

 I really cannot say that I have very much confidence in using AVG, especially the free version. I would rather use Microsoft Security Essentials than AVG. That is my own opinion.

[CaffeineTripp]

Removed the hard drive from the computer, seems that it's just fine.  I can access everything on it.  Currently doing a scan of the main and the recovery partitions on the drive.  Disk Check will be ran next.  Something tells me that the BIOS got updated incorrectly or the battery ran out of juice; power cord is junk apparently, have to wrap it around the computer for it to stay charging.

So, assuming that the person did a bad flash or the battery lost charge while flashing the BIOS (but at the same time the computer was quite usable beforehand and like I said they don't seem very tech savvy), what can be done, or would a motherboard have to be purchased?