Windows 7 IRQL not less or equal blue screen

After looking and your stop code, this is what i came up with.

You have a device that is trying to access memory space 0x4c616205 on IRQ 2 [IRQ 2 covers IRQ 8-15 so it could be a mouse, hard drive, optical drive, graphics card] so it can write to it. The instruction came from memory space 0x8baa8db1.

The first thing you want to do is check to make sure all of your drivers are updated to version supporting windows 7. If they do not have windows 7 compatible drivers, you can try to install vista drivers in compatability mode. If that still does not work you may not have all windows 7 compatible hardware.

You also might have some bad ram.

Let me know your results.

You can copy the files using a bootable OS that allows access to the copy media
Or you can slave the hard drive to another computer - either using the inbuilt connectors or an external drive caddy.

Can you get into Safe Mode? You do this by rapidly tapping the F8 key just before the Windows Splash Screen comes up. It'll offer you a menu - select Safe Mode and press Enter.

Do you have your Win7 installation disk? If so, boot from that and on the 2nd screen select "Repair this computer" in the lower left corner. DON'T go past the 2nd screen if you don't see "Repair this computer"

Once in, select Startup Repair to see if you can fix it automatically.
If that doesn't work, go back in and select System Restore - and restore the system back to a date BEFORE the problem was there.

You cannot "upgrade" from Windows 7 to Vista - it just won't work.
A bootable OS is something like a Live Linux distribution - a CD that you boot from to load the OS. Then you can use that OS to copy the stuff off your Hard Drive.