Windows 7: external device issues since upgrading

Hi, i'm not sure this is the right forum. If not, I apologize.

Anyway I have 3 external harddrives I often connect to my HP Pavilion. They connect fine, and I have no issues accessing data. However whenever I tranfer large amounts of data either way, the drive will just go dead. If I try to access any file on the external HD afterwards it simply can't find it. If I unplug the usb, it still shows as being plugged it. If i try to use the safely remove hardware it will tell me something is in use, and I can't. Basically I have to restart the computer inorder to plug the external HD back in and use it.

Its not just external drives either. Basically anything when tranfering large amounts of data. Recently when updating my iphone it went dead, which resulted in me havning to restore my iphone back to its original settings, which inturn resulted in me havning to tranfer all my music, and videos back onto it. I think I had to restart my computer 20 times before I got everything on it. My little memory stick slots also go dead.

Anyway, I never had this issue until after I upgrading from vista to windows 7. So i'm sure its related. Does anyone know whats wrong, and how I can fix it? I havn't been able to backup my computer in 2 months because of this issue. Any help would be much appreciated.

Here's my computer info.
OS Name Microsoft Windows 7 Home Premium
Version 6.1.7600 Build 7600
System Manufacturer HP-Pavilion
System Model KT334AA-ABA m8530f
System Type x64-based PC
Processor AMD Phenom(tm) 9550 Quad-Core Processor, 2200 Mhz, 4 Core(s), 4 Logical Processor(s)
BIOS Version/Date American Megatrends Inc. 5.24, 6/23/2008
SMBIOS Version 2.5

and incase its important the external HD I have are all seagate, but like I said its happened with my iphone, and even my sony memory stick. So i don't think this part matters.



Thanks in advance.

Check whether "Write Caching" is enabled. Go to Device Manager > double click on Disk Drives > Right click on the disks in question and go to Properties > Policies Tab. If caching is not enabled, you should enable it. But from then on always use "safely remove" before you disconnect a disk.

Try this fix if you have a NVIDIA USB Enhanced Host Controller Interface (EHCI) chipset -
You encounter problems when you move data over USB from a Windows 7 or Windows Server 2008 R2-based computer that has an NVIDIA USB EHCI chipset and at least 4GB of RAM

Thanks. Both those seemed to do the trick.