Best practices for periodic reboot of MS Windows 2003 Server

Question

Hi there,
We are a 4-month old v9.3.1 Essbase environment running on a 8-CPU MS Windows 2003 Enterprise Edition server and we run data loads twice daily as well as full outline restructures overnight. Data loads are executed both via SQL retrieves (ie, from a view set up on another server) and via data file loads after clearing the outline and rebuilding it.
Over time, I have noticed that the performance of the server was degrading markedly and that calculation scripts are taking longer. Funnily enough, the server's performance goes back to what I would expect it to be after a full reboot.
My questions are as follows:
1. Is it typically best practice to reboot MS Windows 2003 servers when dealing with a heavily accessed environment?
2. If yes, is it mentioned anywhere in the Essbase manuals that MS Windows servers ought to be rebooted on a periodic basis in order to perform at their optimal best?
3. Does Microsoft recommend such a practice of rebooting their servers on a periodic basis? I looked throughout their KnowledgeBase but couldn't find any mention of this fact in spite of the fact that it is obvious that a periodic reboot boosts the performance of MS Windows servers.
Thanks in advance for your responses/recommendations
J

Answer 1

A bit of non essential additional info:
We are small to midrange school district who, after close to 20 years on Novell networks, have decided to design and create a new Microsoft network and migrate all of our data and services over to the new infrastructure .   We are planning on rolling out
2012 r2 servers with as much Hyper-v virtualization as possible.
During the last few weeks we have been able to find most of the information we need to undergo this project, and most of the information was pretty solid with little ambiguity, except for information regarding virtualizing the DCs, which as been a bit inconsistent.
Yes, we have read all the documents that most of these posts tend point to, but found some, if not most are still are referring to performing this under Srvr 2008 r2, and haven’t really seen all that much on Srvr2012 r2.
We have read these and others:
Introduction to Active Directory Domain Services (AD DS) Virtualization (Level 100), 
Virtualized Domain Controller Technical Reference (Level 300),
Virtualized Domain Controller Cloning Test Guidance for Application Vendors,
Support for using Hyper-V Replica for virtualized domain controllers.
Again, thanks for any information, best practices, cookie cutter or otherwise that you can share.
Chas.