Windows 7: Can't start up my computer. (Driver problems, BSOD, other problems)

Hi

I hope I'm placing this in the right section, if not, then could someone tell me where to put it and I'll post it again.

I've got a Samsung RV510 laptop with Windows 7 HP 64 bit.

About 2 weeks ago, I was watching a Youtube video, had Spotify and Facebook open too, and my computer suddenly went all BSOD on me.

I turned it off and on again. It came up with a message like 'A problem has occurred whilst loading up your computer, what would you like to do?' I chose 'launch startup repair', which takes a couple seconds, then I choose the other option of 'start Windows normally'. I could get onto Safe Mode. Sometimes it would say 'Operating System not found.'

The computer will then load normally and I can be on it fine.

However, I then started to get Norton Confidential and Shockwave Flash crashes in Google Chrome. I disabled Norton Confidential and thus didn't get that error anymore. Shockwave Flash however did still occur as disabling it means I can't watch Youtube videos and do some other stuff. Sometimes my screen would go blank, and it looks like Chrome refreshed itself due to some problem.

I then used Norton Power Eraser (I have Norton Internet Security 2011 otherwise, and I did many live updates and scans to see if there was anything there, but nothing) to see if there were any problems. It came up with one file that was a possible threat which was msvcrt.dll so I did as it recommended and deleted it. I restarted the computer and now I can't it won't go past the Windows logo without freezing.

I had some start-up error in the past (a few months ago) and I was sent two CDs to correct the problem and they worked. One CD was labelled 'Windows 7 HP 64bit' and the other was 'Samsung RV510 Driver Disc'. I got this laptop, via the disability students allowance, from a company. I haven't contacted the company yet about this problem, but I will be doing so very shortly, because if all else fails, I'm just going to try and get this laptop replaced as I'm not 100% happy with it.

I have put in both CDs in, the driver one doesn't do anything, but the Windows 7 HP 64bit one does. It asks me if I want to continue with the thingy, so I press a button to continue. It tries to fix the start-up, but fails. It says that 'a recent hardware or software change might be the cause'. Then tells me to insert the installation disc and do some other things, but I don't have that disc. The company could give that to me.

It also says 'File: CLASSPNP.SYS Status: 0xc0000098 Info: Windows failed to load because a required file is missing, or corrupt.' This is most likely the msvcrt.dll one I deleted.

I really regret doing all this myself and I should have asked for help sooner.

Can someone please help me? I would really appreciate it.

EDIT: I managed to get onto a 'Windows Memory Diagnostics Tool' memory problem check from having the Windows 7 CD in.

First rule out infection. Try booting into Safe Mode with Networking to run a full scan with Malwarebytes.

If this fails download, burn to CD or write to flash stick Microsoft Standalone System Sweeper, boot it to run a full scan.

Boot into System Recovery Options using the Windows 7 DVD Repair console (option two) and run Startup Repair repeatedly from the list.

If this fails, open a Command Prompt to SFC -SCANNOW Run in Command Prompt at Boot.
If it finds System files to repair it may need to be run several times.

If probs persist, next run System Restore from the Recovery Tools list.

If these all fail, boot into free Partition Wizard bootable CD. Make sure Windows 7 or it's 100mb Boot partition (preferred) are marked Active. Then click on HD to highlight it, from Disk tab select Rebuild MBR, Apply, reboot. If Windows 7 doesn't start, try same again with Active flag moved to Windows 7 partition itself. Next again try running Startup Repair 3 Separate Times with Active flag in original position and then Windows 7 partition.

If all fails, copy out any needed files using Windows 7 DVD or REpair CD: Copy & Paste - in Windows Recovery Console

Then run full Factory Recovery from its partition at boot, Recovery Disks or image you've saved, or the Windows 7 installation DVD following these steps to get a perfect reinstall: Reinstalling Windows 7

If you get it started or recover using factory image, I would follow these steps to Clean up factory bloatware replacing bloated Norton with free Microsoft Security Essentials run with the Windows 7 firewall.