Upgrade to 32 GB RAM

Do you get an error message or..?

crucial.com is offering 8 GB RAM modules, at 1.5V or at 1.35V, for the XPS 8700, so both should work.

The bigger questions are did you get unbuffered, NON-ECC RAM (which is what you need) and what speed is it?

Unfortunately, not all RAM is compatible even if the specs seem to be correct. At least with Crucial, if they recommend it for a specific system, they guarantee it works or they take it back.

THANKS for responding RoHe. I got several different error messages at what I guess is the Windows 8 BSOD. Among them were Kernel Auto Boost Lock Release, Kernel Security Check failure, NTFS File System, and System Service Exception while the system kept rebooting to try to repair itself. I assume the new RAM is unbuffered and NON-ECC but I don't know for sure because it didn't say on the packaging or the Website I ordered it from. The speed is 1600 MHz (same as the  RAM I took out). It's PNY 8GB Dual Channel DDR3 PC3-12800 CAS9 1.5V and compatible with Windows 8. The package says I may need to enable XMP in the memory setting of my PC's BIOS. I took two of the sticks out and the PC will boot with memory in just Slots one and two and the PC info shows 16GB of RAM. However, it did go to the BSOD while I was grabbing a bite to eat while I was replying to your post. Probably should have spent $50 more and ordered from Dell.

Those don't sound like RAM errors to me.

You didn't say how many "old" RAM modules you had, but if you remove all new and put back all old, does it work ok or does it give BSODs?  And check the data cable connection between HDD and motherboard at both ends while you're there, in case you accidentally dislodged a connector while installing the new RAM.

With old RAM installed, you might want to reboot and press F12. Go to the Utilities partition and run extended HDD tests. Lets see If we can get this back to a stable working state.

There are no XMP settings in BIOS on the 8700 so that's not a fix. You mentioned it booted with 2 new modules. What happens if you swap those two for the other two new ones in the same slots? In other words, is one of the new modules defective?

Crucial is likely to be cheaper than Dell and they guarantee it works or they take it back. Many people around these forums (including me) order RAM from Crucial.

I removed all 4 "old" RAM modules. It came equipped with two 4GB and two 2GB sticks (12GB total). I swapped them all with 8GB sticks. I put the old ones back and it was back to normal. Don't know if this was a stupid move or not but I flashed the BIOS (if it ain't broke don't fix it?) to see if that would help. I was running A04 and now it has A11 (or 10 I can't remember now...sucks getting old). No difference, still crashed with four 8GB sticks in. I found that running with 16GB in slots one and two was OK until I actually used a program that would tax the RAM (video editing, etc.) then it crashed like I had all 32GB in. This leads me to believe the PNY RAM is not compatible. I did swap the 8GB sticks around to see if one was bad and it seemed to make no difference. I would order from Crucial except I'm sure they don't take Best Buy or Dell credit LOL. Appreciate your help.

Will it work if you take out the two old 2GB sticks and put in 2 new 8GB sticks, for total of 24 GB?

Will BB take it back for a refund or store credit? At least you can probably find some other nice toy at BB if they agree to a credit. 

Guess you could sell the PNY RAM on eBay and buy from Crucial or Dell...

Did not try to mix old and new RAM. Pretty sure BB will take it back so I think I'm going that route. Always thought RAM was RAM and if you got the speed right it should be compatible but I guess that's not the case. Wondering if there's a list somewhere of known compatible RAM. I see the ones Dell are selling are a lot more. My dilemma is do I want to spend another $100 for RAM I know will work because I got it from Dell or do I keep buying RAM and hoping it will work and at what point does BB or anyone say you bought it, it's yours. THANKS again for your help.

Unfortunately, all RAM isn't created equal...

If you buy it from Crucial, they'll guarantee it works in the system for which they recommended it or they'll take it back with no restocking fees, etc. That's why I always buy RAM from there.

And I suspect they'll be cheaper than Dell too.