I'm thinking that as long as adb works, and you have fastboot.exe somewhere, you should have no problem flashing a PC36IMG.zip without even touching the phone (in fact, you might even be able to get an RUU to work).
To try flashing an RUU, you'll have to put the device into RUU mode (hopefully your computer will recognize it then). To do that, navigate to the folder with adb & fastboot in them, and open a command prompt from there. First, you'll need to connect the device to the computer with USB debugging enabled. Then, at the command prompt, issue the command to reboot the device into bootloader mode:
From that point, the device should reboot into Fastboot (should say "FASTBOOT USB" on the screen - if it doesn't, you're missing a driver). Then, issue the command to put Fastboot into RUU mode:
The device should go to a black screen with the HTC logo. At this point, try running the RUU, and see if it works. If it doesn't, you can try to flash the ROM from the command prompt by doing the below:
- Remove any PC36IMG files from the root of your SD card.
- Copy the PC36IMG for the ROM you want to flash to the folder containing fastboot, and rename to something simple like "rom.zip".
- Issue this command, while the device is still in RUU mode:
Code:
fastboot flash zip rom.zip
The above is essentially what the RUU does anyway

. You should see the file being copied over to the device on the command prompt screen, and then when flashing begins, you should see a progress bar on the device. The command prompt should come back when it's done.
Let us know if any of that works.