Come on, people, seriously.  You'd think that since Windows became a stand-alone operating system starting with Windows 95 some 13 years ago, they would have figured this out by now.  Why haven't any of the Windows releases since then incorporated being able to reconfigure the operating system without ever restarting?

Now it used to be that the whole "You have to restart your computer for these changes to take effect" thing was just a mild nuisance.  Unless it involved drivers, you could just click "No, I'll restart my computer later" and what do you know?  You don't even have to restart your computer half the time.

Has this improved at all in recent years?  No, in fact, it has gotten worse!  There are now artificial measures intentionally put in place to force users to restart.  For instance, after installing Windows updates, you will be prompted every 10 minutes or so that you have to restart until you do.  Or when a program is installed, it will not let you install another program until your computer is restarted.

Device drivers aside, as a developer for the past 10 years, I have never encountered a scenario where any installation step involved in installing a program could not possibly be done without restarting.  Why are users still being required to restart?  Is it because developers are too lazy to figure out how to enable the program to function without restarting?  Is it a "just in case" measure to reduce technical support calls?  Or maybe it has just become tradition.  In any case:

If your installation process requires restarting, your installation process was poorly designed and needs to be reworked.

This is, of course, unless restarting is necessitated by some external factor, in which case, said external factor (e.g. Windows) is a product of a poor design and I hope the designers (e.g. Microsoft) gets grilled for their gross negligence until they correct it.

Home users may simply find this annoying, but when you talk about servers, many of them must be kept up during certain hours, which means that some poor technician has to come in early, stay late, or spend part of his weekend performing updates to the servers, or else the company has to suffer a loss in productivity or even business during the time that the server is being restarted.  This is unacceptable when there is no reason why installing a program cannot be done without restarting.