After the download is complete, launch webOS Doctor:
1.Select you language
2.Accept the license agreement
3.Connect your Pre to you PC via USB and select "Next" when it becomes available
After completion the device will reboot and present you with the activation set-up.
If your PC does not recognize your Pre and you cannot go past step 3 above, try the following steps:
1.With the USB cable connected, completely power off the Pre (hold down the power button until the option to power off appears)
2.Hold down the Up button on the volume rocker
3.While holding the Up button, power on the Pre
4."Next" should now be enabled - proceed with the recovery
The above steps will put the Pre into bootloader recovery mode and should allow the PC to recognize your device and proceed with the restore. In this mode the screen will display a giant USB logo instead of the usual Palm startup logo.