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#11
If you plug you HDD back into your PC does the bios recognize the disk?
Then you could download and boot from the Partition Wizard bootable CD (from the 2nd PC) and see if it's options can make any sense of the HDD. The options are reasonably self explanatory. Delete to unallocate, create to format, surface scan. Just remember to use the APPLY button.
A worse case scenario would be a sudden failure on the HDD controller board.
I think you've gone beyond recovery options? It might be easier to just buy a new HDD and clean install.