my computer is not starting

Clarifications

Like is this a NB or a Desktop computer and what M'Board is being used. What if any changes have been made recently and so forth.

If this is a desktop unit that has a few years on it then the first thing to look at is the BIOS Battery which do go flat and then do all sorts of screwy things that prevent booting.

Or if it is new and never worked look at the BIOS Battery Jumper as some M'Board makers have this set to Disconnect so the battery isn't drained before the end user takes delivery of the M'Board. When you look at the M'Board Manual the Jumper should be set to pins 1 & 2 not pins 2 & 3 but you really need to read the manual on this one.

As you are not hearing any beeps with a normal start this tends to point to the fact that the problem is not recognised by BIOS and because you get the error beeps when you remove the RAM that tends to support the fact that the Power Supply and M'Board are working properly.

If you care to post back with the information I will attempt to help you out.

Col

Check the CMOS battary if fine so remove cmose jumper to clear cmos position and start pc for 30sec after power off system and put the battary on right position and start pc with next reply send motherboard model with type

It sounds like a power supply problem, when you start up your computer enough power turning the fan, hardrives on but not enough power is powering the motherboard.
I suggest upgrading your power supply, pentium 4 can at least run on 400watts.