Hello Ian and welcome to the forums.
Have you exhausted both the Refresh and the Reset options from within Windows 8?
You may need to Google a bit to understand how to use them and what the each actually do, but one, both or either may save you from a complete re-install.
Although a Reset is pretty close to the equivalent.
There is also a third option.....
Called an inplace upgrade/repair explained here Link Removed
It's for earlier versions but generally works exactly the same in "8" if you have the proper installation media (which seems to be seldom the case when it comes to Windows 8).