The replacement drive arrived and not to my surprise the problem was not fixed. I was able to install W7 64bit by doing a BIOS save. It installed fine doing a couple of restarts. After doing a hard restart I got the dreaded 2100 hard drive installation error again.
As previously mentioned the new Toshiba drive works fine, the BIOS seeing it on each restart. I did re-install the modded BIOS to get a different wireless card to work. It does not seem to be a BIOS issue related to the mod, although it might be another BIOS bug that has always been there.
I also tried to load a new SATA driver when W7 was unable to find the drive. The driver seemed to be the correct one but the drive was still not there.
I did find a patch on the Lenovo site http://support.lenovo.com/en_US/detail. ... MIGR-74582
that is supposed to fix HD detection issues but have not had any luck getting this installed. Not sure it is applicable but thought I might try anyway.
At this point i am running out of ideas and am tempted to put back the Toshiba drive although I would like to find a 7200 rpm drive that worked.
Any more ideas appreciated.