I keep suggesting it System Machenic is one of the best tools you can use it your optimize your system. If you have the professional version it has it own AV and firewall built in download it from www.iolo.com
the defrag will take so long because it does a extremely clean defrag makes sure the drive is as optimzied as it can be. And if your running any background programs thens your problem right there
I use CCleaner to clean the crap files off my machine, then RegScrubXP to clean the registry, then I have a created a batch file that defragments the HD (using the windows command line defrager) and then shuts down the pc. Instead of shutting down my pc, I double click the batch file at the end of the day and it defrags the drive and shuts it down. Basically everyday I run CCleaner and the batch file, and every couple of weeks i RegscrubXP the registry. The combo works great for me.
PS. You may also want to use msconfig if you know how, to speed up your windows boot times and free up some resources.