Restart a degree program with a fresh GPA
I'm not sure whether it's common, but my university has a policy like this, called Fresh Start.  A student who returns after an absence of at least five years can have their GPA recalculated, omitting all classes with grades of C&minus; or lower.

As far as I know, they still get to keep credits earned for those classes, and those grades still appear on their transcript; they just aren't included in the GPA calculation.