To customize font size for SAS Log Window:
1) Select LOG WINDOW (Window containing SAS Compile Log Results)
2) Click TOOLS
3) Click OPTIONS
4) Click FONTS…

To customize font size for SAS Enhanced Editor Window:
1) Select ENHANCED EDITOR (Window containing SAS Codes)
2) Click TOOLS
3) Click OPTIONS
4) Click ENHANCED EDITOR
5) Click APPEARANCE Tab