why cant i see my usb flash drive, even though its plugged in, its shown in device manager and i can only see it on other pcs

[Somesortofname]

i look in device management and i can see my drive, i try to change drive letter and it dosn't work, if i want to do something with it i have to go to a friends house. i tried all ports and places i can and i can only view my file on other pcs. PLZ HELP ME (Seagate Expantion portable drive

 

[Boogieman_WD]

Hey there.

How did you try to change the drive's letter? Did you get any error or anything? This is done via Disk Management and not Device Manager. Here's how to do it: How to change the drive letter assignment in Windows.
If that doesn't help and if you have access to your drive via your friends' computers, I'd recommend that you backup your most important data, just to be on the safe side. After that download the HDD manufacturer's diagnostic tool and test it for errors. Try reinstalling or updating all the motherboard associated drivers for your computer (chipset, USB controller, etc), to see if the drive is properly recognized afterwards.
You could also post a screenshot of what you see about your HDD when you open Disk Management and Device Manager. Here's how to post a screenshot here: http://www.tomshardware.co.uk/faq/id-2176231/guide-posting-screenshot-forum.html.

Hope that helps.
Boogieman_WD