I recently had a problem with my pc that i managed to recover from, but it's once again reminded me that it may be asking for serious trouble to put off a request to reboot your computer.
You know the drill -- you run a windows update, or you install or uninstall some software, and you get the dialog saying something like "Windows needs to restart" with buttons to restart now, or do it manually later:
Now I don't know about you but I often click the button labeled for "I'll do it later myself", and tell myself i'll do it in just a minute.
But then time flies and I forget, and don't get around to rebooting for quite some time.
I'm here to tell you that this is really playing with fire and could come back to bite you badly.
The problem is that when windows wants to reboot to finish installing or uninstalling stuff, it has created entries in your registry to do operations like delete directories, replace files, etc.
And if you postpone rebooting, and then do something that could interefere with these operations (like deleting temporary files, etc.), you could be in for a world of pain -- and sometimes you might not even realize you are doing things that would conflict with these reboot-enabled-operations.
I think in general it's also dangerous because when you make a change that requires a reboot, it's probably a very good idea indeed to make sure they didn't change anything that cause you to have problems booting -- rather than postponing the discovery until 10 different things are installed.
Anyway just my 2 cents -- when windows wants to reboot, let it reboot without much delay.