Microsoft's own tech support forums are filled with this non-advice. Either system restore is brought up, or SFC /scannow which rarely fixes anything. Often it really is more time efficient just to do a system reset or start completely from scratch, but if you do have time and the skill to understand the underlying problem it's preferable to learn how to fix it. Reset/re-install teaches nothing.

Any of the mainstream operating systems are tremendously complicated, so free support is probably worth what you pay for it.