My 15 year old PC I used on and off.  I was in our spare room and happened to go into the room and sit at the desk. I do not have covers on the sides so I see the CPU fan laying on the side, interesting.  I find a small plastic tab inside the computer.  I quickly figured the tab holding the fan has broken.  I check the Net and I see this can be a problem.  I have an AMD processor and find lots of whole CPU holder replacements.  I then read / see people taking out the motherboard due to the plastic holder under the MB that the screws for the fan attach to the bracket. I don't want to pull the MB.  So I look and see half brackets for sale.  I buy some for a few dollars.  I then figure if I unscrew only the two screws by the clip that broke, that the other two screws will hold the bottom in place.  I undo the two screws and (carefully) with snippers cut that top part off. I then place the plastic replacement part to find... the holes are too wide ! ! So, with a drill, I make a new hold in the bracket.  Then make it wider and trim off the edges so the screw sits flat in the holder.  The screws are only so long so the screw has to sit flat.  After 4 tries, I got both screws in.  Don't tighten them much at all. I get the fan on (squish it around with paste), get the clips on .. . . .  it holds.  The tab is a bit off but there is lots of leway on the fan bracket. Now the screws fell 4 times on the GPU card trying to get them in. Hoping I did not short anything on the GPU or were I clipped the old holder.  I press the power button  . .  I hear a beep. Screen goes on.. YES... I check the CPU temp.  98- 120 degrees.