So here is my problem. On my XPS 420 I boot the system up and it makes these weird beep noises and then they stop. After that it says on my XPS MiniView at the top of the PC, Memory modules are detected, but. a memory failure has occured. I don't know if this will help but here is my PC specs.
CPU: Intel Core 2 Duo Q6000 Quad Core 2.4Ghz
GPU: ATI Radeon HD 4800 512MB (did have a Nvidia GeForce 8800 or 9800 GT with 1GB)
RAM: 2GB (not sure what type of ram it is plus it used to have 4GB)
OS: Windows Vista Home Premium
Open up the cpu, remove the memory and re-seat it. Not reset. Since it sounds like you've never done that I'd have a knowledgeable friend help you with this. It's not hard but newbie's tend to not reseat it well and that can cause issues too; it takes more force than you'd think, just snaps in as some would say but they forget how scary it is for someone new to this. I don't want you to feel like you'll break it but at the same time we are all different so yes you can use too much force too. If you're a careful person it's simple, just unsnap the white ends on either side of the ram, then pull the ram out. When you reseat it, the module should snap the white ends back into place otherwise you aren't using enough force. That said I've seen instances where it still wasn't seated right. Hopefully like jitpublisher recommended as simple clean and reseat should work; get help if you're not sure.
I know this is a bit too late to reply to this but I managed to FIX IT! I didn't even need to open up the CPU. I noticed that the DIMM slots (if that is the RAM slots) are in pairs such as 1 and 3, and then 2 and 4. I did switching and 1 and 3 worked and 2 and 4 didn't. So yes, thanks for your help!