A couple of suggestions, lose the lines and create a numbered list to the left of the computer on the grey area with the coresponding number placed on the component in the picture, also maybe a different color for the text would look better.
1: CPU
2: Sound Card
3: AGP Card
4: Modem
5: Hard Drive
6: RAM
7: Power Suppy
8: CD-RW
9: DVD Drive
10: Floppy Drive
11: Motherboard
12: Fan
13: ADD THE CASE TO THE LIST
I would like to try making one, what did you use to set this up? did you just use a graphics program to see the coordinates and write them down and hand code them into notepad and save as html? or is ther a program for making webpages that does image maps?