Hi!
 
43 C sounds like a really low temperature for an overclocked CPU. If the CPU-temp rises above 60 C, you should do something about it. But you shouldn't have any problems at 43. The CPU can take temps up to 90 C without taking damage but it probably won't run very stable.

My processor's temp runs at 60°C/140°F in normal conditions, and its not even over clocked. But that is with the original fan that came with the processor, on the box of the prescott it says you should not use any other fan, but I tried the ZubZero and my PC would overheat and shut down as soon as I'm in windows

Thats cuz u are running a P4. Athlon's in general run much cooler than Intel. My athlon 64 runs with OC at 35˚C

The Athlon 64's run pretty cool, but the Athlon XP's are different. True, the Barton/Thorton core is fairly cool, but the Northwood core P4's run pretty cool themselves. The Prescott core is the flaming hot one, and part of the problem lies when it's in Socket 478 packaging. Mainly because S478 wasn't designed for the Prescott core; LGA775 was. In otherwords, your blanket statement isn't true in all cases.

My Processor is only running at 47°C now, not 60°C anymore

Hey Wicked,
 
I am running a little hot
 
60+ Celsius in normal conditions.
 
I realize that it is within operating parameters, but would like to get it lower. What did you do to get your temp down? I have a 550W power supply with a fan on the each side. One fan on the back of the tower and two fans on the front. I could add a fan to the top of my tower and could add another on the side panel, but second would require cutting. I have a ThermalTake Processor fan with Arctic Silver 5 thermal compound. I know adding the fans would help cause the temp drops almost 10 degrees celsius when I leave the side panel off.
 
Any suggestions from the group would be greatly appreciated.
 
_____________________________
P4 3.2Gig, 1024 cache, 800FSB, HT, Prescott CPU
Asus P5AD2 Deluxe Motherboard
1024MB DDR2 Dual Channel RAM
Geforce 6800 GT OC 256MB PCI-Express Graphics
80Gig S-ATA HDD

Hello gurumagic,
 
I had a total of 8 fans in my box and I still ran at 60°C when idling, and up to 80°C when playing games.
I installed water-cooling in my PC to get the temp down to 47°C at idle and 52°C when playing games.
 
To install the water-cooling I had to get a new box, my old one was too small for the 120mm radiator, but it was worth it and now I only use one 120mm fan on the radiator and one 80mm fan for intake.
 
I have photos of the setup from start to finish if you decide to go the H2O route.

just bought a intel p.4 3.4 775. running on a gigabyte ga-8IPE77f pro. 2 fans on rear of case and 1 side. Temp sits around 48-50 normally but tops 60 easy when playing games. A bit worrying since my last cpu (amd 2600+) topped around 42. Stock fan for the cpu is a major pussy. How hard is it to replace the cpu fan with a better one, and any recommendations on the type/brand?

Try anything from Zalman, Coolermaster
 
To replace it you'll need to get the existing one off, exposing the CPU. Then clean up the CPU (get rid of the thermal compound), apply new thermal compound then seat the heatsink on there.
 
Just make sure that:
 
The new heatsink will fit in your case
It's of the right socket type
You use good thermal compound
You clean up the CPU properly (Isopropyl Alcohol -I use 100% isopropyl, most rubbing alcohols use about 70% isopropyl which should be fine also.)
 
Also try Googling for the exact procedure- I am sure there's enough step by step guide out there.
 
Your CPU runs hot out of the box anyway- as previously mentioned. Replacing the HS might help, but I wouldnt expect huge results.