Upgrading memory in a Dell 9100

I am thinking of upgrading the memory in my Dell 9100 work computer. I currently have two sticks of 512MB DDR2 533 in my computer according to Dell Support. When I upgrade, is it okay to add two more sticks of a differant brand(probably Corsair or Crucial) of DDR2 533? Or should I remove the Dell Memory and get a pair of 1GB sticks? My system can support up to 4GB of memory and Dell reccommends installing them in pairs(I'm listening to Dell now, what is the world coming to).

 

Ahhh, someone who shares my hatred of Dell!

To answer your questions, yes, you can use another brand. However, it would be a good practice (as you seem to already understand) to use the same capacities and frequencies.

It might be better to swap out your existing memory for a pair of 1 GB sticks if you anticipate needing to upgrade further in the future (ie this would save you TWO upgrades)