I may suggest you back up your personal files, buy a new hard disk, and throw away the one you're using as soon as possible.
There are no "disk errors" in either version of MinGW, and the likely reason why you had these errors and why unpacking the stable release "fixed" the problem is a hardware failure covered either by sector remapping or sheer luck (different sectors assigned by Windows).
Although it could be a singular failure and your hard disk could work for another 3 years, faulty sectors are generally a bad sign. Whenever I've seen them in the past, they were the heralds of doom.