Xbox 360 Kiosk Discs

[Variation-XBA]

Is the xbox 360 slim compatible with the 20gb hard drive for the Xbox 360 pro?
I received an Xbox 360 S with 4GB of memory of Christmas, but I want to increase the memory size. So, I am wondering if I would be able to use my detachable 20GB HDD that came with my original Xbox 360 (Xbox 360 Pro). If not, then is there anything else that I can do in order to increase the memory?

No you can't use that hard drive, as they are completely different.

You can use simple USB sticks (up to 16GB each) and have 2 plugged in at once (for a total of 32GB whenever you need it).

That or buy the slim harddrive.

[Symmetric-XBA]

a friend of mine had a 120 gb hdd from his old xbox and when he got a new slim he used the 120gb hdd from the old unit. granted it's not something that should b done, and it will instantly void any warranty and you run the risk of destroying your xbox, but it can be done.