USB Hard Drive Slows Computer to a Crawl

My guess is your antivirus is trying to scan the new disk everytime you attach it.
...at least that's my first guess.
The next one involves power option settings pertaining to usb devices.

Quick update - everything works fine in Safe Mode. While in there I altered the setting for "best performance" under the policies tab, which I was told by the mostly useless Dell tech may help. It did not.

Let me list exactly what I do and what happens, as that may offer some insight:

- Fresh boot computer - everything loads fast and normal.
- Plug in external hard drive
- Windows immediately slows to a crawl and the boot disk activity goes to 100%
- I unplug external hard drive but windows continues to crawl
- I am eventually able to click "restart" but another few minutes pass
- I get the "force restart" screen saying that windows is waiting for the following programs to end, or I can click the button to force them to quit... HOWEVER, there are no programs listed there.
- I let it go and eventually it restarts, nice and quick once more.

AARGH!

Clearly, something that isn't loading with Safe Mode is causing this.

Which actually adds validity to my thought, we can pretty much be certain at this point some software package you are running is interfering with data transfer.
I still putt the av at the top of that list even after hearing this.

Snoozing real time should be enough to see if it's the problem
if it isn't we're probably going to have to have a look at your startup apps, to see what could be doing it.

well it's possible whatever is doing it is flooding the logs too, you could try following the steps here to give a copy of the app and system logs.
https://www.sevenforums.com/crashes-d...tructions.html