Changing Resolution settings- unable to do after changing settings for a preso

[rohit.kshirsagar]

Hi,

 My ubuntu laptop resolutions had to be changed for projecting the contents on a display. However I plugged the machine off without reverting back to the older display settings. Now connecting to the projector to do so doesn't work and i've ended up with a login screen with all icons/menus magnified several times over. I can log in but cant view the display preferences screen as everything is too large.

Any way i can revert to the default display settings? Any help would be appreciated.

Thanks in advance,
Rohit