A reformat will clean up things and help you out a little bit, but with those specs, it's still going to be quite slow compared to today's standards.
How Does Formatting a Hard Drive Help Speed Up a Computer? | eHow.com
I agree, reformatting will obviously help to a degree, but, you can't get past the lack of hardware.
nowadays, I recommend min 4gb mem, 64bit OS, and quad core processor..
Most computers nowadays are loaded with 64bit. You would recommend a quad core?
Man, coming from what he has now to a quad core is like going from a 1980's Ford Fiesta to a Lamborghini Diablo (See attached).
yea man that thing is really old
nowadays you can get 4GB RAM, 500GB hard drive and some really fast processors for around $1000
thats light years ahead of your current computer
With those specs, the price would be around 500 or maybe 600.