Athlon XP heatsink problem

They can be difficult when you haven't done many. Here's how I do it.

Orient the MOBO so the CPU is on the right in front of you.
Grab the cooler & orient it so that the step is in the right direction.
Now take the cooler in your right hand & lift up on the mtg. brkt. with your right finger tips, while looking through the side. You'll see when the bend is flat in the center to the left, as you hold up on the right, that the mtg. brkt. holes ar extended below the surface of the cooler.
Hold it that way & put it over the CPU. If you don't hold it correctly the holes will retract & it won't hook on the socket tabs. (I think this is where your problem could lie)!
You may have to try it several times. The key is to keep it flat, (CPU, brkt. & HSF) to the CPU & do as little rocking as possible to hook the left side of the mtg. brkt. on the socket tabs..

Once it's hooked on that side (left side) insert you screw driver in it's slot on the right side.
I put my left hand fingers straight down the sides of the cooler. Then I squeeze my fingers pushing some of my finger tip into the gap between the MOBO & HSF to use as a gage of the gap. This way I can tell if I'm squashing my finger tips I'm putting to much presser on the right side of the cooler pushing down on the mtg. brkt. & not keeping the HSF parallel to the CPU, thus could crack that side of the core. So it's a real good gage for me to tell that I've got the presser to bend mtg. brkt. enough to seat it on the right side of the socket tabs, but have it stable enough that the HSF is remaining parallel to the core.

Even though I've mounted dozens of them now, I still hold my breath each time I do it.

I hope that this helps & you can get it.

Another thing you could do is take it to a shop & have them mount it. Most would do it for $10, some will just do it for you, IMO.

Dazzle them with Brilliance, or Baffle them with BS!

Thanks for the help, but I think the problem actually lies with the mtg. bracket. I got curious and removed the proc and tried to latch the hard side without the proc in the slot and it still would not latch. I think the metal is too thick to fit under the tabs, maybe a manufacturing defect. I will probably rma tommorrow!

I have gone to look for myself. If I return before I get back, please keep me here!