Updated August 2, 2013: Got a super-tips from Kevin Reed (thanks)
As you probably know MDT 2012/2013 and ConfigMgr 2012 defaults the screen resolution to 1024 x 768, but can be customized via the following rules in CustomSettings.ini
If specified, these settings will be written to the unattend.xml file during deployment by the Configure action (ZTIConfigure.wsf script).
Supertip! – Enable Auto Dectection
Previously, I have been using a script that simply deletes the default values from the unattend.xml if the resolution was not specified in CustomSettings.ini, but Kevin Reed gave me a supertip.
For the models you want to have screen resolution autodetection enabled on, simply set the screen resolution to a really low value. This will force Windows setup to autodetect the resolution:
Example with auto detection enabled for all models
[Settings] Priority=Default [Default] BitsPerPel=32 VRefresh=60 XResolution=1 YResolution=1
Example with auto detection enabled for all models but the HP Elitebook 8540w
[Settings] Priority=Model, Default [HP Elitebook 8540w] BitsPerPel=32 VRefresh=60 XResolution=1920 YResolution=1080 [Default] BitsPerPel=32 VRefresh=60 XResolution=1 YResolution=1