|You have NOT supplied enough information. |
Do you hear the usual dong-ding sound when you plug it in like you do when you plug in other USB devices when Windows is running ?
If NO, the USB connection is not getting enough current
If YES, but you also hear the ding-dong sound you hear in Windows when you have unplugged a USB device despite the fact it's still plugged in, the USB connection is not getting enough current.
Are you using a USB cable that came with the external drive ?
If NO, use the USB cable that came with the drive, or if it didn't come with one, the cable should be rated suitable for USB 2.0 devices.
If yes, is it a Y cable with two male USB plugs on the computer end ?
If yes, try plugging BOTH of those in.
Is it plugged DIRECTLY into a USB port built into the laptop's case ?
If NO, plug it into one of those.
If YES, have you tried unplugging everything else you have plugged into the USB ports built into the laptop when you plug it in ?
If you haven't, try that.
If you DO hear the usual dong-ding sound when you plug it in while Windows is running , have you looked in Disk Management to see if it shows up there ?
(Control Panel - set it to display as Small icons, or Large icons, not Categories - Administrative Tools - Computer Management - Disk Management)
READ the info at the link in response 1 !
READ the info at the links in that it refers to !
The same things apply to Windows 7, except for the above example of directions about how to find Administrative Tools and Disk Mangement in Control Panel, and how you find Device Manager - e.g.
Double click on the Computer icon, click on System properties in the top bar, the shortcut button to Device Manager is on the left.