Go to your device manager in "My Grid" as soon as possible. Make sure you change the picklist to all devices ever registered anytime (all devices) to make sure that any old devices show up. Change any duplicates to something unique. It doesn't matter which one. Duplicates can mess up your uploads, and credit may not be given. Duplicate names are only part of what you can see, since it assigns a unique device ID to your computer you can see in your local device display, but not in the device manager.

If he's seriously messed up and the thing burps and sends corrupted units, that may be advised.

If it's just duplicate device names, it's not that big of a deal and is easy to check. If you had 2 devices and start over, you will end up with 4 devices in the device list, since nothing in the statistics database is ever deleted. You still have to make sure that there are no duplicates to eliminate problems with uploads.

I just had a cheapie computer crash yesterday. I will go in to "My Grid" and change the device names to things like OLD 1, OLD 2, OLD 3, ...
Many of us have many more device names around than active devices, because of computer changes or experiments.

I can then register a new computer with new devices and use the same device names I had before. They are sentimental.

Some of us are also experienced with UDMonitor. I have 21 active devices on my fastest computer at the moment. They are running one-at-a-time in an offline sequence.