|Seems odd but the bios may be the place to start. |
There are generally two or more places in bios to look. One is the hard drive order. The USB may be above the internal. Another place may be in removable devices as a boot order over installed hard drive.
I guess it could be an issue with the amount of power the unit may be drawing too. Is it powered by a working ac adapter?
Does this same symptom happen to another computer?
1/3 of highway deaths are caused by drunks. The rest are by people who can't drive any better than a drunk.