Hm, sounds like your running a lot of stuff you really don't need....
What kind of CPU, how much total memory, free memory and HDD space do you have?
First you should delete everything you don't need from the Start->Programs->Startup folder.
Then you can click start->Run and enter
msconfig there to start the system configuration utility.
Click on the Startup tab to see all programs that automatically starts when you boot windows and uncheck everything you don't need (and know what is!!)
Be careful to only uncheck programs you're sure that you don't need, or else Windows may fail to start so proceed at your own risk here!
If you're not sure about a program then you can do a Google search for the program file name (usually a .exe file) and you may find some info on it there.
When you're done with that (and have restarted your PC) then you can continue to defragment your HDD.
Click Start->Run and enter
dfrg.msc there to start the defrag program..
There are also a few other things you can do, but it's best to start with this first..
