Problem statement :

My Seagate Ext HDD fan/electrics died, & I need to recover the files on the hard drive.

HDD appears OK.

I read somewhere that I could take the HD out of the Seagate enclosure & connect it to my PC (Dell Dimension 2400) after I had removed my PCs native internal hard drive.

Then save the files from the newly installed HD to another external hard drive

My question is - when I remove my Dell internal HD & replace it with the HDD from the Seagate External enclosure, won't I have to install Windows on it to be able to see whats on it & save the files - which will wipe clean the newly installed HD I am trying to save ?

If you remove the PC's internal primary hard drive, you will no longer have a bootable drive. Basically, Windows will not be there to load as it is stored on the primary hard drive.

If the drive is still OK, you can purchase an external HDD enclosure for it that is USB 2.0. That way, you can continue to use it as an external drive.

Otherwise, you will have to set the drive as slave and connect it to the slave connector on the primary IDE channel cable. I would suggest going the external enclosure route though.