You can't just replace the motherboard and expect the computer to reboot. There are sometimes even problems if you are replacing same brand and sometimes even the same model.
You need to reinstall the OS and any of the applications you want.
Some time ago I had my HP computer in the repair shop. One problem after another meant that I wouldn't get my computer back for several weeks. Because I needed info on the hard drive for my work, I removed the drive, took it home, put it in an external drive case and copied what I needed. (yes, I back up regularly - but not often enough!).
Anyhow, I bought a new computer that has now been acting up, so I thought it wise to get the old HP back up. Intel mother board (3 GHz) replaced with a (ugh!) FoxConn. Do I need to admit that I can't for the life of me find that old drive?
What do I do now? I have a new 160 GB Western Digital drive. How do I get the computer to boot? Is there any hope?
As usual, thanks in advance.