What would you choose between these?

B is better, an external hard drive would give you portability.

I would suggest against a notebook, unless you are really going to use it that way. As in if you are traveling most of the time, and need to work from remote locations/ need to use your notebook on college campus etc.

If it suites you, get your desktop updated, noting like having a mean machine desk !!

It seems you have a pretty old computer. It's hard to send you a recommendation because some computers are that old it isn't worth upgrading them.

If the computer was purchased as a budget computer before the year of 2006 or a top of the line computer built before 2004. I would suggest buying a new computer or perhaps a second-hand one.

For approximately $300 you could buy a second-hand dell with 1gig ram and 320gig HDD. You can add your current ram and HDD to make 2gig RAM.

But it really depends on the use of your pc.

Is for office work? ()

just for surfing the web? (buy a $300 ASUS Eee PC Laptop)

Are you looking for portability but more performance (buy a better laptop)

If your looking to work with intensive video editing and gaming I'd suggest buying a new system.

Upgrade none of them, and buy a notebook.