I have a six year old Dell!

I have lots of space on the internal hard drive.
I have lots of space on an external hard drive.
I have Disckeeper 2010 to clean my drives.
I have used PC Doc Pro v5. to remove all bad files.
I have used Driver Whiz.

BOTTOM LINE: it is running slower than molasses in January!

I can't afford a new one and don't want to get rid of this one anyhow!

HELP!