Why does my heatsink not fit into my motherboard?

[evans1]

I took my heat sink off to clean the dust out of it because my CPU was overheating. I took it off, cleaned it out, and now I took the thermal paste off and reapplied it. Then I went to put my heatsink on the CPU with the four pegs and 3 of the 4 pegs go in. It's not alligned with the hole at all and I can't understand why it won't fit in. I'm thinking the plastic expanded when I remove the pins.

Intel i5 CPU with stock heatsink and fan.

 

[chrisso]

You might need to rotate the heatsink to get it how it came out..

 

[evans1]

No it says it should fit in any way, and even though it says that I've tried it every single way rotated.