Is it safe to do this with an external hard drive?

I have a 160 gb usb external hard drive.
(1) Is it safe to keep it on for more than a couple hours and play music files that are on it?
Someone from Dell said it's not a good idea keeping an external hard drive on for any length of time.

(2) Is it safe to download programs to the external hard drive, so as not to have any of the program's files on the main hard drive, and run them?

Thanks, -Rob

 

I saved the installer to my desktop, then installed the program on my external hard drive(F).
The program seems to be running fine.
I was hoping to avoid having any spyware on my computer, that might come with this program.
Thanks, -Rob

 

if you have a cheap enclosure, or even the one that came with the HD is poorly designed, the Hard drive can overheat if left on all day. That happened to my dads external HD. It was a piece of crap. It was made out of plastic and its supposed vents were designed by a monkey. His actually overheated and died. If you have the money I would invest in a nice enclosure that will properly cool your HD, or ensure your current enclosure cools your HD decently. Some just need a simple mod to cool. Just open your enclosure and feel your hard drive after letting it sit connected to the comp for a few hours.