SymptomsAfter upgrading to Parallels Desktop 6 or 7, there is no Internet connection on the virtual machine.
Right-click (Ctrl+click) on My Computer --> Manage --> Device Manager --> Network adapters and check if there are the "!" signs:
The status of the device will be as follows: "The device is not working properly because Windows is not able to load necessary drivers. (Code 31)".
ReasonThe drivers for the network adapter were not correctly installed by Windows. This could happen cause of unexpected reboot during network driver installation.
SolutionRight-click (Ctrl+click) on failed Network Adapter and choose "Delete". Repeat the same for each network adapter with "!" sign.
Right-click (Ctrl+click) on Computer in the Device Manager and choose Scan for hardware changes.
The network adapter should be connected properly. Restart Windows and check if the Internet connection is working now.