Tradesman1 :
Give them a try, if problems, try raising the DRAM voltage + 0.05, if still problems let us know mobo, CPU and model#s of the DRAM
These are all old stuff, because i don't have money right now for anything better and honestly i'm okay with it.
Intel C2Q Q6600 (non overclocked)
I don't know the motherboard as i don't have the PC, i'm planning to buy it for a reasonable price
rams are 2x2GB Apacer (golden coolers i think) and TakeMS also 2x2GB (ddr2)
I wouldn't recommend myself raising voltage or anything because it probably uses some old cheap power supply.
However if you are getting these free then you can always try it, the worst is it won't work and either won't boot or will crash.
I have already 4GB of them so I guess they are free.