when i try to install windows 7 on my 2nd hard drive i get that the selected disk is of the GPT partition style and contains one or more dynamic volumes that are not supported for installationYou could try installing an op sys to your other drive, set it as the boot drive then see if Zero Assumption Recovery can get you anything back from the suspect drive - trial download here (you'll have to buy it if you find it can help):
Download critical data recovery software - computer data recovery with ZAR.
Then read up on good backup practices!
I think your first priority is to grab any data that is important to you, off the drive (If possible!). Download and burn a live cd from the web and run it. I would reccomend Knoppix
KNOPPIX - Live Linux Filesystem On CD
I use this for troubleshooting computers with similar problems to yours. Even if you are not familiar with Linux, you will find it easy to use.
Provided the hard disk is working, at least to read, then you will be able to access it in Knoppix and transfer all the files you need to a working hard disk, external, perhaps, or to any other media (USBs etc. If you have two cd burners installed, then you can copy the data over to an empty CD.
There are also an increasing number of websites which offer backup facilities. Example:
Online Backup, Data Backup & Remote Backup Solutions | Mozy
There are some new technologies being placed in operation that behave differently form what most of us are used to. Because of that, I have to ask where did the GPT drive come from. Are you or were you using a UEFI enabled system?
If you do not know what UEFI is, there may be an option in your system bios for how to boot your system. You may have an option of Bios or UEFI. If you do have that option, you migh try selecting the other option to test.