You can do this with a tower but there is a more effective way to do it if you don't need to capture and ill be posting that instructable soon.
Also im going to post an instructable on how to do this with s- video because it gives you a better video quality.
Please rate if you like this instructable. If there's something wrong or its not working leave a comment.
Step 1: My system
Windows Version: Windows Vista Home Basic
windows experience rating: 3.1
Processor: Intel(R) Pentuim(R) Dual CPU T2370 @ 1.72 GHz 1.73GHz
Memory(RAM): 3062 MB
System Type" 32-bit operating system
Step 2: What you need
1)A EasyCap usb Capture card
2)A usb extension cord (optional)
3)Three RCA female couplers
4)5 RCA cables (i used 1 yellow, 2 red two 2 white)
5)Two RCA splitters
6)L/R RCA to 1/8 plug
7)1/8 female to 1/8 female coupler
8)1/8 Headphones/1/8 Speaker
Most of this stuff you can get a radio shack. the only thing you can' t get there is the easycap usb capture card. you can get the easycap on ebay but i would avoid that because theirs a lot of fakes that ether have crazy lag or don't work properly.