This is just a little fun post because I keep reading about how P4's are very hot and the stock fans suck. For 4/5 years I've built and owned Intel based PC's. Never had any problems with the sock parts.
Alright I must admit the gray little pad of thermal grease sucks big time. NEVER EVER leave that crap on! Strawberry jam would give you better thermal conductivity. (though I don't recommend that) So simply go out and buy yourself some Arctic Silver 5. IF applied correctly it will be just fine.
Another little thing about the stock heatsync and fan is the mounting. Something I think is great. The snaps. As long as your mother board is correctly mounted it should pop in nicely. I hate the idea of having to remove the board to put in enthusiast fans. (there's a little bracket)
With these to conditions you should have acceptable temperatures. Two little notes. When applying thermal paste don't put too much, all you need is a thin layer. You can check the contact putting the HSF (heat sync + fan) on and then removing it to check it's made good contact. You can easily tell were it's correctly touching.
P4 530 3GHz HT
Leaving the computer on for 10-20 hours a day. My temperatures are 39C to 48C at full load (room is 25C). (Full load up to 52 for me when my room is 28C)
P D 820 2.8 before putting on arctic silver.
That guy is a hot bastard.
47 to 59 at full load.
The temps droped 5C with the silver after it cured.
P 2 duo E7200 2.53Ghz
27C to 33C at full load
Oced to 3.16Ghz
30C to 43C
Well that's my little ramble. Questions or comments welcomed.