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This is a known issue with Microsoft Update KB3013455, released on the 10th February 2015.
For a quick way to check if you have the update installed, open a DOS command prompt and type:
wmic qfe list brief /format:texttablewsys | find "KB3013455"
If this returns no text at all, the update is not installed; if it is installed, you'll see
KB3013455 and more text printed out.
The issue can be resolved by either
uninstalling the update (but this will leave you with a security vulnerability). A reboot will be required.
Installing a subsequent update (the Microsoft official fix, released on the 18th Feb 2015):
To resolve this issue, install update 3037639. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
3037639 Fix for text quality degradation after security update 3013455 (MS15-010) is installed.
This fix will take you to a page where it seems you're downloading the original KB3013455 all over again. Keep going, when you actually click to download you will get an option to get the fix, KB3037639.
A reboot will be required.
The fix was later included in Microsoft's automatic updates in March 2015.
Edit the list below to add affected systems:
- Windows Vista SP2
- Windows Server 2003 SP2
- Windows Server 2008 SP2
- Windows XP (for people on the Custom Support Program that keep receiving patches for XP)
- Windows FLP
- Windows Embedded (WEPOS, POS Ready 2009)
Edit the list below to add affected Fonts (only some font sizes show problems):
- Courier New
- Times New Roman
- many others
Description of the problem (from here):
Essentially the small fonts (8-20pt) that normally result in a one-pixel line (think of lowercase "b" or "t" or "d") would now be a random mess between 1 and 2 pixels. Turning on "Clear Type" or font smoothing does "smooth" the garbage and it doesn't look as awful but that doesn't make the text any more readable.