Troubleshooting external hard drive please

I'm having trouble with my external hard drive! Indeed it to run on different computers since I and generally is recognized without drivers! it's been 3 years since I have!

Now suddenly, I have the following message "a device attached to this computer has malfunctioned and windows does not recognize"

For early information, the hard disk works on another computer. Currently I have to reformat the pc but nothing happens!

Prior to resettlement, it was recognized from the time I install the firm "optimize pc"! I did a scan, I find it at least 150 errors, then repair bulls*** I delete everything!!

the errors mainly concerned activex ! I delete everything and from that moment it no longer function


Who can help me please, thank you in advance for a response
Happy New Year 2009

Did you just reinstall windows or did you really formatted before reinstalling?

If you formatted, the influence of PC Optimizer is now zero regarding your external hard drive ... is something else.

Have you done a windows update after reinstalling windows?

The USB port where you connect the disk does it work with other devices (key, camera, webcam ,...)?

Look in Device Manager when the drive is connected to see if there is no error message