Hey everyone. I am having an absolute rotten day. Argh I have a home pc, I put it together myself. It was a Gigabyte MA770T-UD3P board with an AMD Phenon II X4 955 Black Edition processor coupled with an OCZ 500w power supply. Other internals are a GeForge GT220 video card, a 300Gb drive, 1Tb drive and a DVD writer. It had 2GB of RAM (Kingston ValueRam KVR133D3N9). The other day I decided to install an additional 4Gb of RAM. My board has 4 memory slots, with the 2GB RAM in slot 1. Since my board recommends putting similar RAM together, I put the two 2GB sticks (PATRIOT Sector 5 PGV34G1333ELK sticks in slots 3 and 4). The PATRIOT sticks are bigger than the norm, so I have to put them there since the CPU cooler prohibits me from putting them in slots 1 or 2. Power On, the BIOS shows 6Gb of RAM. And it boots and comes to the login screen, but the Keyboard isnt working. Ok, so shut down and restart, but nothing this time the system doesnt even POST. One light comes on and I can hear a hard drive make a read/write sound but the CPU fan doesnt come on either (even when the heatsink becomes pretty hot). So I shut it down thinking power is inadequate and disconnect the DVD drive. Power On, and nothing. Same disk sounds but nothing else. Remove my old RAM - the Kingston, leaving the PATRIOT in there. This time, system boots. So I shut down the system thinking I can just use 4GB ram and hook up the DVD writer. System comes on, but now there's no Keyboard. Argh. Shut down and restart and again the system doesnt POST. After trying things on and off again, I finally get DVD and Keyboard working and everything is fine and dandy. However, now System monitor only shows the system showing 2.7GB RAM instead of the required 4GB. Is the power supply inadequate? I looked up the specs for other power supplies (upto 750W) but they all show that they provide the same wattage 155W to the 3.3v cable. Any ideas people? I tried everything, and am clueless.