I have two WD500 blue drives that were in a raid 0 array. I have since taken one drive out and put it into another computer. Windows 7 64 install doesn't see it. If I boot into the other hdd, it sees as a healthy formatted disk. Does this have something to do with the drive being in a raid array? I had the same issue with two old WD250s after having them in a raid 0 array. One was fine the other was not seen by Win 7 install.
I suspect the problem's origin is that the former RAID HDD has some unusual info written into its Partition Table because the way RAID writes stuff is NOT to any universal standard. You'd need to get rid of that for Windows Install to figure out how to use the HDD.
The easiest thing that MIGHT work is this. When you first start the Install, choose a menu option to Delete any and all Partitions already on that HDD unit. This MAY allow the Install routine to re-write info to the Partition Table without caring about the old info, and then it might work.
If that does not work, your best bet might be to get a HDD utility able to do a Zero Fill of that HDD. Since your old unit is by WD, go to their website and download their free utility package, Data Lifeguard, which works on WD products. IF you can use a different computer with a functioning Windows and mount the old HDD in that temporarily, you could install Data Lifeguard's For Windows version and use that. IF, however, you can only do this on a machine with no OS installed, get the For DOS version as an .iso file image and burn it to a CD. This makes a bootable CD you can run from with NO functioning HDD or OS in your machine, and you can use it that way. Either way, run the Zero fill routine on your old HDD. Two IMPORTANT notes: (1) be VERY SURE you run it only on the old HDD you are trying to "fix" because it will wipe out EVERYTHING on that drive!; and, (2) the job may take several hours because it has to write and read every Sector.
The Zero Fill will wipe out everything on the old HDD and check it thoroughly for Bad sectors and fix them. When done, the Partition Table will be absolutely blank, just like a brand new HDD from the factory. Then the Win 7 Install should have no problem using it.