Symptoms
You have a MacBook with Retina display with a Windows Virtual Machine and you experience any of these screen resolution issues in Windows:
- Windows screen resolution is low - the screen looks blurry
- Windows icons are very small or big
- Windows screen resolution is very high - everything looks tiny
- You have an external display connected to your portable Mac computer
Cause
Windows Operating Systems (as well as others) were not adapted to such high pixels density (DPI).
Learn more about MacBook Pro Retina Display: Frequently asked questions about using a Retina display
Resolution
Parallels Desktop 8 provides enhanced Retina display support for Windows 7 and Windows 8 Virtual Machines. Go to Virtual Machine menu ► Configure... ► Hardware ► Video to see Resolution options for your Virtual Machine:
Please use this Troubleshooter to solve display issues on a MacBook Pro with Retina display. You may also learn more about Virtual Machine Resolution options for Retina display at the bottom of this article.
Note: The Resolution settings shown on the picture apply to Windows 7 and Windows 8 Virtual Machines. Resolution options are different for Windows XP and Windows Vista Virtual Machines.

Troubleshooting: Windows image is blurry or scaled

Troubleshooting: Windows resolution is too high

Troubleshooting: Windows Fonts ans icons are too big or too small

How change DPI scaling in Windows? Please check this article http://windows.microsoft.com/en-US/windows7/Make-the-text-on-your-screen-larger-or-smaller
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