Changing formats

I recently upgraded computer including a larger monitor.
When I now run my databases, they fill about 25 percent
of the new screen. How can I enlarge my databases to fill
more of the new screen? A couple of other questions -
when screen previewing a report, how can I get the
preview to automatically open at 150%? Also on reports -
how can I ensure a group header is attached to its data
when a new page is opened. ie. the group header should
not be on one page and the group data on the next.
many thanks