I'm designing various unsizeable forms and layouts in Delphi to run on Windows. I'm worried that if I assume a minimum 1024x768 screen size (or greater), I'll run into customers still using 800x600. What minimum screen size should I assume? I don't want to require a minimum that irritates users. What's the best practice or current reasonable assumption for screen size?
Tell us more about your audience, because that's what it depends on.
A few examples:
With the current demise of 4:3 screen resolutions, the upcoming of 16:9 resolutions, and netbooks, the 1024x600 resolution is now very popular as is the 1024x576 resolution (compatible with 576i).
For desktop sytems, the HD video resolutions 1280x720 and 1920x1080 are becoming more and more popular.
For installing software, make sure you can run on 640x480 for a couple of reasons:
lots of sysadmins don't install non WHQL video drivers because they make their systems less stable since it takes a while for modern video hardware to get a WHQL driver, the most recent hardware often runs on 640x480
on Windows Embedded Standard systems (the majority consisting of Windows XP Embedded based systems, Windows 7 Embedded was recently released), the same holds: often it takes a while for special embedded versions of the drivers to appear, or they don't install video drivers at all because they device will run as headless systems.
--jeroen