To be honest. Reinstalling is usually the fastest option. Well, for me it is.
I've most of my settings exported to my flash alongside the setup files for pretty much the only 8 or so programmes I use.
A full reinstall usually takes me less than two hours out of which I only spend ~30 minutes in front of the system.
I dunno, most windows related problems are caused by drivers being outdated, if so, it's around 10 minutes to get the new drivers and installing it, while installing Win7 takes around an hour (Win7 Pro x64).
I find fixing problems much less problematic since after re-installing windows you will still eventually run into the problem again, when fixing the problem lets you off the hook entirely, also going through the windows updates again, I just can't be arsed to go through that shit over again.
Fixing problems = feels good, cuz you won't run into them again.
Re-installing Windows = feels le~gay, cuz I wil lrun into them again eventually 
i did that, years ago. Now im computer problem tired so i dont go the long way of search the internet for newest drivers and the latest versions.. i let the young people do that. Windows have a staff of a few 1000 people who update the drivers and repack the windows update section so.. why should i do their work?
If someone pay me $ / hour to look for drivers im happy to do it but if i do it for free, no thanks. Besides, the diet windows get from a clean start is well worth the 2 hours you put on it.
facts about windows:
1: it will gain size even if you dont install anything
2: it will create bugs and errors even if you keep the computer in a one state mode
3: windows save temp files and some is impossible to remove, unless you format to a clean state.
4: its windows, it was never made to be used for a longer time.
so to say it the best way, if you have the time and energy to spend a few 100 hours looking for new drivers for everything in the computer i wont stop you or say anything bad. I have been working with computers for 18 years now, i know what to do and what not to do. Clean start works best for me, i do it once every year so the time spent on it isnt really that much.
Setting up my system after install take me 20 - 25 min since i know exactly what i remove and keep. Same with system settings. Total install take around 1-1,5 hours.... not so much time wasted.
I know people do registry cleaners and temp file cleaners but since 99% of them create problems by removing important keys etc im not going to experiment with them. I play alot of games online and the updates i get from time to time kind of create the problems (old files downloaded to win temp folder etc) so in that case a clean start is well worth doing. If you use your computer like your grandpa do you can have it running for 6-7 years but you never change anything, no new programs, no new setting, no new nothing (like a one state system).
We are all using our computer for different things, the more trash you may collect from updates and program or game updates the more changes you do. More changes = more temp files and corrupted reg keys or left over files.
Windows update: Im forced to look through all the different updates and run it on manual mode since windows want me to install software like -removal of hazardus software- or how they spell it (cant be uninstalled after install, only thing to do is to redo all work again to come back to clean start) and -silverlight- (server software, why do i even need it?).... and we have our old time favorite -internet explorer 10- worst web browser you can get.
-For those (not me thou

) that use copied software the tiny program to remove bad software its doom to get that thing in your computer since you cant uninstall or or use the restore program to get rid of it. It will remove everything micro$soft thinks is "bad" and it wont even ask you if its ok. If m$ was able to they would put in firefox in that list too.