Windows repair doesn't detect unbootable Windows as installed

RolandJS said:

Leave the 299MB Active. If still nogo, try marking the system files partition as Active.

I already tried both several times x 3 restarts.

Bump

Destroy666 said:

What about SFC reporting missing unfixable files and the repair utility broken ACP.sys one time? Why is noone talking about them? Are they false leads? Couldn't this/those file(s) be messed up by some kind of a virus or whatever? What could be the reason for SFC saying it/they can't be repaired?

Is it possible that your hard drive is failing and that is why you are getting messages about unfixable files and the like? Can you hook the drive into something like a drive enclosure and browse your files or is that not an option because of the bitlocker?

As I mentioned, my system driver is not encrypted, only an additional data driver. I also wrote about chkdsk result and that it possibly was root of the problem, but files seem to be readable. Which files exactly should I check?

Bump. Can I transfer acpi.sys from another 7 x64 system or is it machine-specific? Or is there other software for fixing corrupt Windows file(s)?

Bump.

Is there any other alternative forum with repair specialists where I could try asking? I feel so helpless.

What happened to your system so it didn't work? You wrote that it began with no sound and then it didn't boot any more. I suspect that it could be a disk failure.
What kind of disk format you have: UEFI GPT or Legacy MBR?
Do you have saved the Bitlocker key on a Pendrive or paper?
My suggestion is:
- Disconnect all drives.
- Connect a clean disk and install your Win7 on it. No need to update or activate.
- Connect your data disk with Bitlocker and with the key try to have access to it. If you do, make a unlock backup of all.
- Disconnect your data disk.
- Connect your system disk, right click properties, tools and run error checking. Depending of what kind of error an how many it finds, I'll suggest to reinstall Windows (clean install, reformatting the disk).

Sorry for late reply, but I felt so angry and helpless that I completely avoided that PC and I only used laptop in the meanwhile. I found motivation to come back to this topic though.

It's MBR, I've already fixed errors with chkdsk /f /r and I took Bitlocker disk out. I still don't know what can I do next:
1. /sfc /scannow with /offboot from disc reports files that can't be fixed for some reason, they're in CBS.log which I have no idea how to view
2. One of these files is probably ACPI.sys (because an error said that once), since it's a driver I assume I can't just copy it from another machine. How can I fix it then?

Is there really nothing I can do?