Clean out your driver cache folder reboot your PC and plug in the WBFS drive it should redetect it. (all your USB devices will be redected) This may or may not work but its worth a try.
I have the same problem, but on Windows 8. I tried this solution, but it didn't work. Some history:
- I set up a Wii to work with USB HDD loading ever since that first became available. This meant manually formatting an HDD to WBFS.
- When plugged into Windows, it would always ask for formatting. It did recognize it as an HDD, just not the format. Anyhow, it still detected it as a drive and WBFS managers just worked.
- Later on I started to encounter some trouble. Most WBFS managers didn't detect the drive anymore. Windows didn't list it as a drive anymore either. I did find one that detected it though. Since I had so many games on it, I was reluctant to reformat.
- Started to use a new laptop with Windows 8. Same problem as before, but that 1 program did work.
- After a reinstall of the laptop that 1 program doesn't detect it anymore either.
It is still listed in the bios, but I am unable to do anything with the drive. It is also listed in the device manager, but as a unknown USB device and I can't do anything with it (except turn it off). It's not listed in partition manager at all, leaving me unable to assign a drive letter to it. I also tried other partition managers that aren't built into Windows, but no success either.
The Wii still reads it just fine though. Is there any way for me to reformat is? Is there a USB loader that formats the HDD through the Wii? And no, this has nothing to do with getting enough power from the USB, this HDD has its own power supply