I have a Compaq Deskpro EN with a 20GB HD. It works perfectly. I moved this drive to a different (non-Compaq) computer and it will not work. I've tried using Maxtor Magic and moving the 20GB to a 120GB drive which now works in the Compaq machine perfect, but again if I move the 120GB to a non-Compaq pc it won't work... Why is this and how do make the drives work in a non-Compaq computer, WITHOUT having to re-install or formatting the drives?
The problem seems to begin after POST and during the first read of the MBR. I tried to repair and also overwrite the MBR which didn't change anything. both of these drives still work and boot perfectly on the Compaq, but when I put them into the new machine it hangs everytime on the intial read of the MBR, which is what leads me to believe there s something Compaq writes to the MBR the keeps them from loading in other machines..
It could be an incompatable driver for reading the HDD. Check under system - Hardware - advanced and compare the the drivers for reading the HDDs. I assume the compaq is an old system and your other system is new.
Will the HDD boot in the other computer in safe mode, if so boot to safe mode and delete the Hardware drivers that are different, reboot again and reinstall the correct drivers. If You cannot, You can try removing the drivers using the Compaq in safe mode. Then power off and swap HDD's. CAUTION You may lose the drive, But you may have to remove the partition and reload anyway. Unless someone else has a better Idea.
Side note - When swapping a hard drive to a newer system it is normally better to just delete the old HDD (Remove/reinstall Partition) and reinstall because of possible driver conflicts.