New HP Pavilion 763 P4 (Runs like a turtle)

[David Clifton]

I've just bought a brand new HP Pavilion 763 Pentium 4 2.53 Ghz running Windows XP Home Edition with 512 MB of SDR ram that has been all updated with the lastest service packs but, the system takes forever to open programs and reboot.
I've went into the device manager and set the computer to run for optimal performance in the settings tab on the device manager and still the system is very slow,even slower than my 800Mgz system.
Any ideas of what to do ?
Thanks Very Much