Okay so I have a big catch 22 of a computer issue. I'm going to type this out a bit weird, mostly for my own sake to make it easier.

One day I try to run Security Essentials to check my computer. Get an error that says a file is corrupted and it cannot complete scan. Tells me to run disk check. Cannot run disk check or schedule a disk check when the computer starts. Do some digging on google. Run chkdsk in command prompt, that doesn't work, but I figure out a way to find out where shit is going bad and what file is corrupted (don't remember how, but involves a notepad file). Turns out some file involved with disk check is fucked, which means windows cant auto fix the problem/auto replace the file (disk check is needed for that). This also makes it so I cannot restore my computer to a previous date.

I'm running windows 7 64-bit on a laptop. The only solution I've come up with is that I have to re-install windows or replace the file with the one on my original windows 7 disc, which I do not have nor do I have access to any windows OS disk (don't recall my laptop ever coming with one. If it did it's gone).

So, there you go. Please help save my sweet old laptops poor little life! I was planning on waiting till the release of windows 10 and just starting from scratch, but there hasn't been a release date announcement yet so I don't want to wait any longer.

Have you tried running chkdsk with any extra commands, like /f or /r?

@gaff: well this all started a few months back, which is when I was researching it the most. I might have done something like that, but can't quite remember; what do the different letters signify?

Edit: I think I did chkdsk /r. That's how I got the notepad file which told me which file borked the process

Is your computer bootable?

You can burn a new installation disc by downloading an iso from Microsoft:

http://answers.microsoft.com/en-us/windows/forum/windows_7-windows_install/where-can-i-download-windows-7-iso-i-have-a/7d964b05-2be9-4800-bc7f-3ca30356fc3d

I'd recommend running system file check to potentially repair any corruption. To do this run command prompt with administrator privileges then run sfc /scannow. Shouldn't take a huge amount of time, if any corruption in the Windows install is found it will attempt to restore the corrupted elements. If this fails because the store are corrupted you will need to repair those first then re-run sfc. To repair the stores you'll need to run dism (Deployment Image Servicing and Management), from the same elevated command prompt run DISM.exe /Online /Cleanup-image /Restorehealth. That will re-download any corrupted information stores from the Windows update site. Once dism has done it's thing you can re-run sfc which should at that point successfully complete and repair any corruption on your install.

There is very little cause to re-install Windows these days since there is quite a lot of automated repair functionality built in.

@korwin: ran sfc, didnt work. ran dism just now and it says "error: 87" and "The restorehealth option is not recognized in this context".

Drop the restorehealth, that one is windows 8 or greater.

@korwin: now it says "an error occurred while processing the command". Also it still says "error: 87"

Try with the /spsuperseded flag in lieu of the /RestoreHealth

@korwin: Okay, so dism did it's thing, but then I ran sfc and it still says it was unable to fix some corrupted files. Looked at sfc details and it says autochk.exe is corrupted and some other stuff "says autochk.exe source file in store is also corrupted". It also says something about a hash mismatch, which I have no idea what that means.

If all else fails...most modern Windows laptops have a recovery partition instead of coming with physical recovery media. Try Googling "mylaptopmodelnumber recovery partition" and see if it ships with a factory recovery partition and what the instructions are to go back to that state. It's usually just a single step at boot.

If it doesn't have a recovery partition or your recovery partition is corrupt, you could try extracting your Windows 7 key from the machine (if you can't see it on the sticker on the bottom of the laptop) and then downloading an ISO of that version of Windows. Make a bootable disc with something like Rufus and reinstall with your original key.

The downside to either one of these solutions is that you'll wipe everything...but you backup important data, right? The upside is you won't have a years-old crusty ass Windows installation anymore.

Here is a resource with links to official Windows ISOs:

http://www.techverse.net/download-windows-7-iso-x86-x64-microsofts-official-servers/

The hash mismatch means that SFC is looking at the file, expects a certain result but what is returned doesn't sync up (odds are the version of autochk is incorrect somehow so it doesn't match when sfc does the hash check).

Try installing this autochk hotfix, it should replace the existing copy - http://support.microsoft.com/kb/975778