Ive put together a new comptuer and fairly ceterain everything was installed correctly. When i turn the system on everything seems to working fine except that the fan led's dont turn on (not a major concern.) however, nothing apears on the monitor. any help would be greatly appreciated. i have an antec 300 case with a Asus P5P43TD Pro motherboard
Check to make sure that you have all power connectors from your PSU plugged in correctly. Many new builders forget to plug in the CPU power connector, usually located near the CPU itself. In your case, with a socket 775 processor, its probably a 4 pin connector. Also check to make sure that your video card is installed properly, and that it has all of the necessary power connectors connected as well.
If you can confirm that everything is plugged in correctly, we can move on troubleshooting more components, such as the RAM. Let us know.
The first step in troubleshooting this problem is to perform EVERY step in the READ before posting about boot problems! sticky at the top of the forum. It was created to troubleshoot this exact problem and will solve the problem 90% of the time.