Dell Studio XPS 16 Won't Boot, Help Please

I bought this laptop about 9 months ago. The specs are as follow.

Intel® Core™ 2 Duo P8600 (3MB cache/2.40GHz/1066Mhz FSB)
MEMORY 4GB Dual Channel DDR3 SDRAM at 1067MHz (2 Dimms)
Video Card ATI Mobility RADEON™ HD 4670 – 1GB
Hard Drive 320GB 7200 RPM SATA Hard Drive

I am running Windows 7 Ultimate with everything up-to-date. Everything has been running smoothly on this laptop until yesterday when I tried to defrag it and got a BSOD. So today I started it up, and everything was fine, so I decided to try and defrag it again. To my frustration, I got another BSOD, except when I tried to boot it this time, I get a "Windows Recovery Error" that says "Windows failed to start. A recent hardware or software change might be the cause". My two choices from there are "Launch Startup Repiar (recommended)" and "Start Windows Normally" none of which work. If I select the first one, a black screen appears and a cursor which I can control, but nothing else (I let it run for several hours). The other option just gets stuck on the Windows is Starting screen with the flag pulsating its colors.

I really need this laptop for university in 2 days, so any help would be much appreciated, thank you in advance.

PS. The defragging program I used was Perfect Disk 10 by Raxco.

 

I've heard bad bad things about that program. It is definitely possible that it borked the install. Try running running check disk if you can by going into safemode if your able. The only other thing that I can think of is the that hard drive may be going bad.

Edit: If you need it for school in 2 days you can just format it and reinstall - this will tell you if the hard drive is bad or not. Try to boot in safe mode to get any files you need - I always keep an image of my hard drive on a back up drive for my laptop and desktop incase of this type of stuff.

 

Thanks for the quick reply, when I tried to launch safe mode, it got stuck on this file Windows\system\32\DRIVERS\CLASSPNP.SYS for a very long while, then went into the login screen except it didn't show the login box or anything except the background and the cursor.

I'm guessing the defragger messed with this file, is there any way to fix it?

 

Run a repair install of Windows

Sounds kinda like when my HD went bad in my 1640

 

Ok I did some reading up on this issue. So fare it all points to a virus...

 

Insert windows CD and boot from it and choose repair windows. If you can backup files before it will be perfect, but using repair option you shouldn't loose any files.