RAM counting slow on bootup

Hello all:

Usually when you boot a machine, the RAM is counted very quickly until the amount installed is reached. When I boot my PC, my RAM is counted in 4’s until it reaches 512MB. Why is my RAM taking so long to be found? It’s taking my machine 10 minutes to bootup. The RAM is recently installed, but it was working fine for about 2 weeks, but all of a sudden it’s doing this. HELP!!!