I own a Dell 530 Inspiron and someone else asked this very same question in another thread.
Here's what you need to know:
Careful on the ram upgrade, your motherboard may not be able to handle more than 4GB's regardless of the OS (32Bit vs. 64Bit) you install or how much physical ram you try and put in.
There were 5 different models of that motherboard. Depending on which model you have, you can only have 4GB's, some models allow 8GB's.
See page 110 of the owner's manual. You can download that at Dell's support site after you enter your service code. Look for "Manuals" on the left side of the page.
You'll have to open your case to identify what mobo you have, then scroll through the pictures of the different models in the owners manual to identify which model you have.
Then page 179 lists which models will hold what for maximum memory- 4GB or 8GB.