Parallels WorkStation 2.2, 50-99u, EDU, ESD, DE WWL2XL-A04-DE ユーザーズマニュアル

If you receive a poor picture or incorrect system behavior when switching a guest operating 
system to fullscreen mode, this can be fixed by configuring your primary OS settings. 

When guest OS is running in fullscreen mode, physical display is switched to guest OS 
resolution with the highest possible frequency. If your physical videocard or physical monitor 
do not support the resolution or frequency requested by the guest OS, substitute video mode that 
matches best is set instead. In some cases substitute mode may not work, or you are warned of 
an inability to switch to fullscreen mode. To fix the situation, correct primary OS display 
settings: 

1  Open  Display Properties window by selecting in Windows Start menu the Settings/Control 

Panel/Display. Make sure that the Hide modes that this monitor cannot display option is 
selected in the Setting tab. If not, select it and apply the settings. 

2  If the option in the previous item is selected but problem remains, make sure that the proper 

monitor and videocard drivers are installed in the primary system. Reinstall them in case of 
necessity.  

When a guest OS is running in fullscreen mode, the physical display is switched to guest OS 
resolution with the highest possible frequency. If X Window System is not configured for the 
mode requested by guest OS, substitute mode that matches best is set instead. The situation is 
worse if the physical monitor does not support the requested mode while it is configured in X 
Window System. Parallels Workstation can not know that the monitor does not support the 
requested mode and will try to switch to it. This may lead to poor picture quality in fullscreen 
mode. 

If display picture in fullscreen mode is unusable: 

1  Stop the guest OS, 

2  Reconfigure X Window System to exclude resolution/frequency inconsistent with your 

monitor, and restart X Window.