Obviously, something is fucked up on that disc. You could try to boot up your machine using a different operating system - such as Damn Small Linux (if you have more than 128 MB of RAM, it can run entirely from memory) - and see if it can access the data.
You could also try booting into command prompt (or into Damn Small Linux) and using the appropriate version of DMDE to recover the data from the drive.
Another option is stuffing the thing into an external enclosure (USB/eSATA/FireWire, whichever your machine can use is OK), starting the machine without that hooked up and then connecting and turning on the enclosure after the system boots.
If it freezes then and there, bad news (altough I'd suggest you try again under Linux if it happens under Windows - just to make sure).
If it tells you the drive is not formatted or doesn't recognize the partition (but recognizes the enclosure as such), DON'T agree to format the drive if Windows asks you about it. DMDE has some chance at recovering your stuff even then.
DMDE can be downloaded here:
http://softdm.com/download.html
The trial version can't perform batch recovery or recover entire subdirectories in one go - you have to choose and retrieve one file after another - but has all the features of the full version apart from that.
I'd also suggest you use MHDD to check the hard drive's SMART readouts (post them here for reference):
http://files.hddguru.com/download/Software/
Scanning it for bad sectors is another matter - possible if you read the readme and are CAREFUL which options you choose. Knowing your level of computer knowledge and the fact it's easy to accidentally wipe the drive, I suggest you only go into that if everything else fails (or else just leave it to your brother).