I purchased a Dell Studio XPS 8000 sometime ago but when I tried to upgrade the memory from 8GB to 16GB, I ran into some problems. First off, here are the specifications of my PC, which will hopefully give more information for anyone who is willing to help me troubleshoot my predicament: Dell Studio XPS 8000 Chassis Serial Number: 5WWXML1 Running Windows 10 - 64 bit Processor a Main Circuit Board b 2.80 gigahertz Intel Core i7 860 32 kilobyte primary memory cache 1024 kilobyte secondary memory cache 8192 kilobyte tertiary memory cache 64-bit ready Multi-core (4 total) Hyper-threaded (8 total) Board: Dell Inc. 0X231R A01 Serial Number: ..CN736049BM0169 Bus Clock: 133 megahertz BIOS: Dell Inc. A03 12/21/2009 Chipset: Intel D131 rev 17 The original memory configuration that came with my Dell Studio XPS 8000 is as follows: 'DIMM1' has 2048 MB (serial number F2E2172B) [Slot 3- Black] 'DIMM2' has 2048 MB (serial number F5E2172B) [Slot 1- White] 'DIMM3' has 2048 MB (serial number 02E3172B) [Slot 4-Black] 'DIMM4' has 2048 MB (serial number 06E3172B) [Slot 2- White] I had a total of 8gb of memory. I replaced it with Corsair (Vengeance) DDR3 8GB (2 x 4GB) This was inserted into [Slots 1 & 2 White] with Slots 3 & 4 Black left empty. I had planned on buying another pack of Corsair (DDR3 8GB (2 x 4GB) if the 8GB worked, therefore bringing me to the maximum amount of 16GB of memory which is all the motherboard can handle according to specifications. However, when I booted the computer with Corsair (Vengeance) DDR3 8GB (2 x 4GB) only 4GB of the 8GB registered in the Bios. I rotated the strips and they were both good. When I went to switch back to the original configuration that came with the computer: 'DIMM1' has 2048 MB (serial number F2E2172B) [Slot 3- Black] 'DIMM2' has 2048 MB (serial number F5E2172B) [Slot 1- White] 'DIMM3' has 2048 MB (serial number 02E3172B) [Slot 4-Black] 'DIMM4' has 2048 MB (serial number 06E3172B) [Slot 2- White] My PC would not boot and made a continuous beeping sound. I am no longer able to use the original Dell memory in any configuration.Therefore, I am stuck with Corsair (Vengeance) DDR3 8GB (2 x 4GB) that was inserted into [Slots 1 & 2 White] with Slots 3 & 4 Black left empty. Slot 1 White with 4GB of Ram being the only memory recognized. The 4GB in Slot 2 White does not register in the Bios and is not seen by other software utilities that I have tried. Hopefully you can now see my frustration and realize that I now have less memory available to me than originally came with my PC. I read through many internet forums and tried all sorts of different things to solve the problem but the results are always the same leaving my PC with only 4GB of memory to be accessed. I’m guessing that there must be something wrong with the motherboard but I’m really not sure. Unfortunately, Dell has been of very little help. Not sure what my next step should be, but if there is anyone out there that can assist me, it would be greatly appreciated. Thank you, John M.