How do i format my external Harddrive?

Chances are that the PS3 file format is not recognised by windows, or the drive is flaged as disabled and set to power off when not used.

If you format it, then any data on that drive will be forever lost.

If you can connect your PC to the PS3 and transfert data from one to the other, then reconnect the drive to the PS3 and transfert your data to the PC.

Now, from the PC point of view:
That drive is surely flaged as disabled. And if it's also set to power off to save energy in the power management, then the drive totaly disapears.

Open the device manager and open the properties for that drive.
You'll notice that on the general tab, at the bottom, you have a list box that say: (the exact wording may be different, I use the French version)
Do not use that periferal (disabled)

Change it to:
Use the periferal (activated)

Click OK to close the dialog.
It should take effect immediately, without any need to reboot.

Kualinar
March 2010