Your computer will definitely not be able to connect to the EggBot until the driver installed.
I have not seen this error before on Win 8 or XP. It sounds like you may not have permission to install the driver on your system.
Use this version: https://code.google.com/p/eggbotcode/downloads/detail?name=UBWDriverInstaller_v20.exe
To run it, right-click and run as administrator.
