SymptomsI see a yellow exclamation mark on the Printer icon in "Devices and Printers" folder in my virtual machine.
CauseParallels Desktop 7 has a Shared Host Printer feature, which enables you to use your Mac OS printer in Windows. Before it works Parallels Desktop tries to install a virtual printer inside the virtual machine. However such printer installation may fail inside Windows 7 or Windows Server 2008 R2 virtual machines. As a result you may experience the above behavior.
ResolutionPlease upgrade your windows installation to Service Pack 1.
Here you can find Information about Service Pack 1 for Windows 7 and for Windows Server 2008 R2.