The Crucial Memory Configuration Tool.
One of the best tools I have seen on the market.
So good, it is what I do each and everytime a customer asks for additional memory. I've found Dells that didn't offer the same information on their specification sheets. I would guess others are the same.
So when it's time to upgrade no matter who you use it's always good to have a memory company take the guess work out of what memory you need and how much you can use.
Here's the link: http://www.crucial.com/systemscanner/
Watch the video before you do anything so you know how it will work.
If you have questions copy the URL and send it to me via the contact us link here. But, if you look at the prices and shop around I am going to guess you'll end up buying directly from them.
They also have a good assortment of SSD (solid State Drives) which I haven't tested. I'm still using the Intel SSD's which are really nice.
Have a good memory upgrade!
If you need help doing the actual upgrade call me once the memory comes in and I'll stop by to help. Check the service rates and I'll make sure your PC is tuned up the way it should be.