I have a problem atm. I bought 3 rams (all Crucial 2GB DDR2 800MHz CL6 pc2-6400 )... Well, everything came in. so i dismounted my current one (some random one, i think its cl5) and mounted all the ram in... now when I pressed the power button everything lights up, but screen is black, keyboard backlight off etc... no beeps nothing. Its like its not getting any power. So i went on the internet on my phone and checked out some answers... many said take out the mobo (MSI Global P45 NEO) battery out for a minute or so and put it back in... did that, didnt work. So I took 2 ram out and one stayed in. still nothing. So i took them all out and placed the old one back in and everything worked.... so I went to the bios settings and did set up everything for the new ram (made it so its 1,8 V and cl 6 etc...) still didnt work after redoing everything.... so I got an Idea. I placed the old one back in and took one of the new ones and putted that with the old ram. Now the PC booted up. I checked cpu-Z and it said i have 4 GB of ram (new ram stick + the old one). after like a minute the pc crashed (old ram got stressed too much (I still had the new settings 1.8 V and cl6)). So this is the problem. I cant use the new ram. I want the old stick out and 3 new back in. I have tried a lot of things. Right now I am installing a bios update, maybe that will work. the mobo should not have a problem with CL6 or 800Mhz.