After a repair you must re-apply the service packs and roll-ups.
After uninstalling a Service Pack or roll-up you must also repair Visual Studio before re-applying them.
Question
What happens if:
At this point, do I need to install SP1 again? In simple words, is the Repair Installation intelligent enough not to overwrite newer versions of files (from SP1) with the old ones that it has? Or is it that the Repair Install will simply bulldoze everything to original state?
Solution
After a repair you must re-apply the service packs and roll-ups.
After uninstalling a Service Pack or roll-up you must also repair Visual Studio before re-applying them.