sigh. and I wanted things to be perfect... and I was going to rely on my SSD for readonly storage (and maybe I still can). I already knew about "bit rot" (increasing bad disk blocks problem in hard disks as outlined by Steve Gibson) :-/ well, reality sets in...
this is the reason why I have to reinstall windows every 1-2 years, with hard disks, etc. it's the disk drives themselves. what I have also learned from the spinrite forum, is that some model of hard drive has a firmware bug in which zeros are written instead of data.
- programs appear to have more and more bugs. they don't work right. things start acting worse and worse over the period of a year or more.
- program crashes
- blocks of garbage characters in your data, or a program can't read a particular file. this can happen sometimes to floppies over 3 years old and not so much to hard disks. some floppies last for 10-16 years. pray over your files beforehand?
fixes for firmware bugs
obtain a firmware update for your hard disk or SSD from your storage vendor.
read the instructions/PDF that come with it first, the firmware update may destroy data or it may not. I would think not.
then in windows explorer, click downloads, right click the program you downloaded and pick run as administrator to install/run the firmware update.
fix corruption problem with Silent Data Corruption (SDC), for 1-2 years
- wipe with active@ killdisk or other disk zeroing program and reinstall OS/windows/linux using recovery discs you can buy. it's bootable.
- refresh your windows installation. XP: repair. windows 7/8 install and do an upgrade or repair. it especially helps if you have a retail version of windows, but you will have to spend 2 days reinstalling windows and drivers.