If I understand you correctly, when you plug in the external Hard Drive (EHD) things start going slower on your computer, but when you unplug the EHD or turn it off then the computer works at normal speed? Is this correct?
If so, then I don't really see how reformatting the EHD will change things, at least not at this point. That being said, it is an easy enough operation to do, and I don't see any harm in it, as long as we are talking about reformmating the EHD and not the hard drive on your computer.
How is the EHD powered up? Do you have a power cord that plugs into the wall, or does the EHD get it's power from the USB ports? Sometimes EHDs require more power than a USB port can put out, sometimes requiring two USB cords to be plugged in together (if this is possible in your case even. If so they must be plugged in together, say within a second or two of each other).
How old is this EHD? Is it making any noises, such as squeeks or squeels? If so, then this is a sign that the EHD is going bad.
What driver are you using to install the EHD in your computer? Did a disk come with the EHD when you bought it, or did you just have to plug it into your computer, wait for a minute or so, and then it worked properly (because Windows already had the proper driver)? If you installed a driver from a disk, then I would suggest going to the manufacturers web site and see if any new driver is available. Download and use the new one, not the one on the disk.
I would think going to the manufacturers web site and see if they have experienced this problem before and what they suggest to cure it.
Just some ideas, I hope it gets you off in the right direction!
Edited by Albert Frankenstein, 01 January 2006 - 07:46 PM.