Is the only difference that you upgraded from SS03 to SS08, the overall operating system was upgraded too, it's a whole new computer or even that you changed from a standalone workstation to a networked one? Any number of things could cause a slowdown - a new computer that doesn't have swap file size set correctly, a previously standlaone box that now has to deal with network transmission traffic, etc.

The problem with slow computers is that most of the time. It's all to do with a hidden part of your system .This part of your system is called the 'registry' and is a huge database which stores all the settings and options for your PC.The reason why the registry is responsible for making your computer run slow is because it is actually prone to getting corrupt and damaged. Because Windows is constantly using the database when you're using your computer, it's constantly got 100's of registry files open. This unfortunately means that Windows gets confused, leading it to save the registry files wrong, making them incredibly difficult for your computer to read. Think of them as files which are all jumbled up, making your computer have to spend longer to read them. You just need to be able to clean out all the damaged files from the registry, allowing Windows to read all the files it needs, when it needs them.And to do this, you just need to use a tool called a 'registry cleaner'.I should like to commend Registry Easy to you !http://clean-computer-run-quickly.com/