Question Does ddr2 1066 slot accept ddr2 668

most likely yes. normally the advertised number is the max speed it can handle and it works will slower speeds as well. if you want to be 100% sure post the motherboard model and can look up the specs for it and see.

if you don't know, install speccy and it will tell you what you got.
 
The slot has locks on each end that should be pushed away from the ram slot. The socket itself is keyed, there's a plastic piece that has to line up with the slot on the ram. If it doesn't fit in either direction, then verify that you actually do have the right kind of ram and it is ddr2 and not sdram or ddr3 or laptop ram. And yes, it should be a hard tight push to get it seated, there's teeth in the socket that have to make contact with the tiny gold lines on the ram.
 
The slot has locks on each end that should be pushed away from the ram slot. The socket itself is keyed, there's a plastic piece that has to line up with the slot on the ram. If it doesn't fit in either direction, then verify that you actually do have the right kind of ram and it is ddr2 and not sdram or ddr3 or laptop ram.
Yes ik it’s a fb dimm and my motherboard doesn’t support it
Thanks for all the help anyways