When you change your screen resolution, make sure you are clicking "keep" in order to apply the screen resolution and keep it.
1. Open Screen Resolution by clicking the Start button, clicking Control Panel, and then, under Appearance and Personalization, clicking Adjust screen resolution.
2. Click the drop-down list next to Resolution, move the slider to the resolution you want, and then click Apply.
3. Click Keep to use the new resolution.
Hope this helps!
Microsoft Windows Outreach