windows refuses to boot (startup recovery loop)

[Julius Caro]

So I have had windows 7 pro x86 on an imac for a while and now I can't get it to boot. For 2 months it worked without problems. Now it won't boot: when the windows boot animation is supposed to kick in, it suddenly changes to the 'old' vista logon , and it goes straight to the startup recovery tool. The thing is unable to identify the cause of the problem. Reading the longs, I can only see two things "norootcause" and "autofailover" or something like that.

Steps I've taken:

- Press F8 at boot, try any other mode. ALL of them go to the start up recovery, including the different safe modes and the low res vga mode. The only one that does something different is the "use last known good configuration" or something like that. That one starts to play the windows logon animation, but then a BSOD is shown for a split of a second then it reboots.

- Press F8 at boot, selected the option to disable automatic restart upon failure (or something along those lines). I did that hoping I would be able to see the BSOD on the next try, but this option goes straight to the start up recovery tool as well.

- Since the partition is still accessible, I've tried from OS X to look for the minidump folder in the windows folder, but there isn't any. So I have no way of knowing what the BSOD is. If there is any other folder or file I should be looking for a readable crash dump / log, please let me know!

- Booted from the windows 7 installation DVD and tried to use the recovery tools. The startup recovery there does the same thing as always (can't find the cause, can't fix anything, can't even tell what the hell it has to fix to begin with)

- Tried a system restore, I can see the restore points and select them, and it seems to go through all the steps needed to restore those backups, but in the end I get a message that says that it couldn't be done.

- Tried chkdsk /f , at some point it did seem that it found something and fixed it, but the boot problems persists. Everytime I runk chkdsk from the DVD recovery console, it says that everything is correct but that it couldn't write to the logs or something.

- Tried to install windows 7 over itself (kind of a 'repair installation'), but it says that the installer has to be launched from windows itself for that to work.

- Tried to use some command to look for corrupted/malicious system files, but it didnt work. From the x:\> prompt I tried launching the command (cant remember the name), with the options needed to scan a 'separate' disk (otherwise it will just try to check the same volume), but it didnt work either.

- I have discarded a hardware failure since OSX works just fine. OS X is rarely ever used on this computer, so the last EFI update happened long before the windows failure. So I have discarded a bootcamp thing as well. The night before the problem, I had installed the drivers of a usb phone for skype. I've tried booting the pc with NOTHING connected to it other than the keyboard and the mouse, still the same problem. Safe mode should work if it was that one faulty driver, but it doesnt. And the computer went through a few boots with that driver before failing.

Any ideas?

Since the partition is still accessible from OSX I already have a full backup of the disk. I know I can format. But for emails and such it will be a lot easier to do the backup from the mail clients themselves.

At this point I dont care if I have to delete all the drivers from the windows folder and let windows restore the microsoft ones. I just need to get it to boot. There hasn't been a single windows installation that I have not been able to boot in situations like this.