Cable select pitfall
With luck your C: drive is jumpered as Master on a standard IDE cable. My only major data loss was when adding a second HDD to an ICL 486 IDE Cable Select (CS) system. I had failed to appreciate the niceties of CS and it went belly-up. And sometimes the Master drive could be at the end of the cable, at other times in the centre. I worked on an HP Pavilion P4 recently whose BIOS/hardware seemed to insist on Cable Select (a correctly jumpered and cabled Master/Slave setup was not recognised). [Some may remember Laplink and serial crossover cables as a means of data transfer on old machines.]