Weird boot problem in Windows 7

Hello.
I have a Windows 7 32 bits ultimate version which doesn't boot like it should. It gives the error of not shutting down normally. If I click it to Start windows normally it shows Starting Windows and after 2-3 seconds it says "Windows is loading files" just like it starts windows repair or install. The problem is it shouldn't because it was a working OS. If I choose "Launch startup repair" it shows the same screen but restarts the computer after 2-3 seconds. Disable AROSF doesn't help because there is no BSOD - just a restart always. Safe mode also says "Windows is loading files" and restarts without BSOD.
Windows was working normally so it must be an updating issue. I tried all the common possible commands (chkdsk /r didn't report problems) and especially bootrec.exe (/fixmbr /fixboot /rebuildbcd says 0 found windows installations) and it didn't helped. I tried sfc /scannow but of course it doesn't allow me because it thinks there is a repair pending. I even tried ERD commander for Windows 7 but it didn't allow me to uninstall hotfixes (cannot find any) and couldn't start the recovery environment for some reason. The automatic repair in Windows 7 recovery console (from the dvd) gives those two errors:
"Root cause found:
Boot manager failed to find OS loader."
and
"Repair action: File Repair
Result: Failed. Error code = 0x490
Time Taken = 4767 ms"

Memory and HDD are tested and okay!!!

I think it is BSODing, but because of a failure to dump the memory to a file (or it happens so fast) that the system is automatically restarting from the BSOD faster than you can see the blue screen.

Try this: tap F8 prior to Windows logo to get the boot menu like you would when going to Safe Mode, but select "Disable automatic restart", then attempt to load Windows normally. It should have the same issue except this time show a blue screen. If it does, record the details on it such as name of driver/module (if present) and the bugcheck code, followed by the 4 hex parameters in parentheses.

It doesn't give BSOD this way. I just wrote it shortly "Disable AROSF" Also now I cannot run SFC /SCANNOW no matter what I do!
Here is the second error I received (the first was with the pending repair which I fixed with the offline sfc commands) :
"Windows Resource Protection Could Not Start the Repair Service"
And after I fixed it starting the windowsinstaller service or something I get the third error IN A ROW:
"Windows Resource Protection Could Not perform the requested operation"
I guess sfc could fix my problem but the problem is even starting it! Here is an interesting thread:
SFC Windows Resource Protection could not perform the requested operation FIX!
Problem is I cannot edit the registry from the DVD and I cannot enter the Windows in any way.

oh ok, I didn't know what AROSF meant so I disregarded it, lol.

It's evident your MBR got totaled as any attempt to recover it or restore any existing partition on the drive is failing. I'm not sure how the MBR got messed up or deleted as only means I could see that could cause it to be tampered with would be through a rootkit MBR infection or a failing hard drive.

If you want to try to resuscitate the MBR and any existing partition it looks like you're going to need to use something like TestDisk to find any existing MBR and partitions and recover them that way. If it proves unsuccessful at finding or recovering any, I have a feeling your hard drive is dying and is in a degraded state. You should use a bootup version of Seatools to test your system drive for any potential failures. Run all basic tests on it. Note that Seatools is not guaranteed to find that the drive is bad, but it helps. If any test failure occurs, the drive is most likely bad and must be replaced.

Both Seatools and TestDisk, amongst a myriad of other items of value, are on the UBCD, which I recommend you burn onto a cd using another available PC. It also has PartedMagic, a liveCD environment that you can use to access contents on your drive, perform a myriad of disk-related tools and data recovery stuff, and a whole bunch of other goodies. If the stuff on PartedMagic and TestDisk can't find your partitions, then they're gone for good.

You made the attempt to remove the pending.xml file, but did you also make sure that you were running SFC on the recovery environment on the Windows disc and not the drive? You will also want to use the OFFBOOTDIR and OFFWINDIR args for SFC to specify boot and windows directory paths, as instructed here. If that doesn't work, there's a good possibility it cannot find any partition tables or MBR, hence the 0x7B bugcheck. Again, this can easily be caused by corrupted partition table/MBR and/or a bad drive.

"I typed exactly this and it doesn't help. I can access all the partitions from other computer."

So you've put the drive in another system and yet somehow that system can see all the partitions, but when you put it in the PC that is suffering, applications like PartedMagic cannot discover any of them? If that's the case, it sounds less like a drive issue and more of a motherboard problem with a faulting drive controller and/or BIOS.

"But it really must take like 30-60 minutes for a real system file check even on fast computers so there is something fishy here. Why it doesn't scan the system drive???"

If the drive has a LOT of files on it than yes, it can normally take well around that long to do a CHKDSK run, longer if you have it look for bad sectors as well. However, if it's unusually long without not having much space used up, then it's conducive - again - of a failing drive.