I cannot read file panel font. How can I make panel font larger?

The file panal font follows system-wide icon title font setting. To change icon font, go to system Display settings (via Control Panel or by selecting Properties from desktop right-click menu). Select Appearance tab. In Item drop down menu select “Icon”. Use Size menu next to Font to change font-size. Note that this description is for Windows 2000, it may differ slightly on other systems.

Note that currently WinSCP is not able to reflect settings change on run-time. So you need to restart it to make change take effect.