[SOLVED]How can I get 1920x1080 resolution for a 23" Flat Panel in Win7 VM?

[GermanTux]

Thanks a lot Old-Polack!, very clear instructions.
What a joy and what a difference, Now the Host, the Win 7 VM and the Linux VM looks very nice. Now I have to solve the issue with the Linux VM that do not allow seamless mode, but that has to be a Guest additions problem.
You saved my day  
Regards
joejac

to use seamless mode, you must install Virtualbox guest additions from virtualbox, and not Synaptic.  The command to do this is Host + D (usually right-control + D), then drop to a command line and run it.  

su <enter root password>
sh VBoxLinuxAdditons.run

you will the need to reboot the vm when finished.   

[joejac]

Thanks a lot GermanTux! very clear.

It worked fine, I marked this post solved. Now my last issue is the sound, but that is in another post.
Thanks to all for your kind advices.
Best regards
joejac