dual boot system 10 on C:, 7 on D:
Search indexing insists on indexing drive D: instead of C: No matter how many times I uncheck indexing locations on D: and choose proper locations on C:, when indexing starts to rebuild it reverts back to D: I though I had solved by temporarily turning of driver letter D:.

The indexing then happened on C: and things seemed good, so I turned D: drive letter back on and now the problem is back.