Memory Question

it won't work

your computer, at a guess (hard to know without actually having the specs), has two memory "banks," and those banks require two memory cards per bank. Because the memory bank works as a unit, if you install only one memory card in a bank that needs two to function, then that bank will not work. Whether this will cause a system crash or just a slowdown...hard to say. It's possible that the machine will return an error on startup and refuse to boot.

 

http://support.dell.com and find your user manual. That will have the exact answers for you.