Windows 7 - Windows won't start

I hope that I don't post here something already answered before.
I've been using windows 7 for a while on a dual boot with windows XP. Both are 64 bit versions and worked just fine for 6 months. The problem appeared a month ago when windows 7 won't start. I started the computer, chose Windows 7, blackscreen with windows logo came up but then another black screen and the computer got back to the bios. When I run the selfdiagnosys mode it couldn't fix the problem and gave me the following problems:
Problem Signature 01: 6.1.7232.0
Problem Signature 02: 6.1.7232.0
Problem Signature 03: unknown
Problem Signature 04: 2120172
Problem Signature 05: AutoFailover
Problem Signature 06: 7
Problem Signature 07: 0x6b
OS Version: 6.1.7232.2.0.0.256.1
Locale ID: 1033

If you have recently attached a device to this computer, such as a camera or portable music player, remove it and restart your computer. If you continue to see this message, contact your system administrator or computer manufacturer for assistance.

I tryed it again and again, but the same issue came up. Tryed memory diagnosis o hard disk check but no help. Same issue with same list of problems.
It is any way I can fix this, without reinstalling windows?

yes there is. if you boot in the other OS navigate to the OS that is blue screening. On that drive youwant to go the windows folder then the minidump folder (?:\windows\minidudmp, zip the dump filoe (*.dmp) and upload it to us for debugging.

Let us know if you need help with any of this

Ken

The windows/minidump folder is empty! and
windows\minidudmp doesn't exist.

I gotta go to bed now. But I will look here tomorrow ASAP for replys. Thank you very much for your help! I hope that you can help me.

Can anybody help me? Please!

Is there a file named MEMORY.DMP located in the C:\Windows folder?
If so, zip it up and upload it to a free file hosting service - then post a link to it here.