I have two PC. One HP 8200 Elite with Q67 Express chipset (has i5 2nd gen init, got problem no post, has 4 beeps, tested the rams all OK) I wanted to test the cpu by putting it in a Dell 9010 Q77 (has i5-3rd gen init). Is it ok? they have the same socket 1155.
No, it is not ok. The BIOS on the Dell 9010 must support the processor. If it does not, you could damage the processor, or the motherboard, or both.
To put the if 2nd gen in the Dell 9010, the 9010 has to be socket, chipset, AND BIOS compatible.