Run System Information located in the Start Menu, Programs - Accessories/System Tools. Copy the Summary information and paste it in a post here. This will help us determine exactly what your system has.
Jumping from 3.3xx to 4.11 is a huge change. There have been a whole lot of features added and of course the more you add the harder the computer has to work. Even if you haven't used any of the new features some of those are still running in the background.
Have you done all the items on this checklist (which is also in the manual)?
http://www.mtu.com/upgrades/hoster/v...de-hoster4.htm
What it had you set will not hurt the computer and has nothing to do with the message you are getting about the processor speed. Hoster has two checks that it does now which are for processor speed and memory. If either of these do not meet the recommended minimums then you get a message telling you that it doesn't meet minimums (not those words but what you are getting or that memory is to low). This is why I want to see your system information.