Booting a different OS install is a good idea. Personally I'd move it to my Linux box and go from there. For those who don't have that option I suggest using a boot CD like
Parted Magic or
SystemRescueCD and use the tools on them to troubleshoot the drive. Partition Magic has been deprecated for a long time now, and I don't think that Symantec even sells it any more. I don't know why so many people recommend this obsolete and dead product so much.
You wrote "under disk management says: dynamic and invalid" which I presume is the Storage/Disk Management section of the Computer Management control panel for Windows 7. (Correct me if I'm wrong.) Have you tried converting the Dynamic Disk to Basic Disk? Note: this is done on the left panel, not the larger right panel that shows file systems. This may be all you need to set things straight.
Another tack is to boot from one of the above Linux-based boot disks and run their utilities.
The thing I do if all else fails and there's not data that I want to save on that HD is to determine the Linux device name for the HD in question (something like /dev/sdb) and from a command prompt as root run `dd if=/dev/zero of=/dev/sd?' where "?" is the correct letter for the bad drive. When it's done (may take a while), reboot and try to write a fresh partition table onto the HD. If that works, boot from the original Windows 7 and see if you can create a new partition. If that works, format it and try putting files on it.
If it doesn't respond to anything, go to the manufacturer's website and see if they have a utility to test your particular drive. (Usually one utility covers all models.) IME the utility will give you a code if the drive is bad, and instructions about how to return it if it's still under warranty.
