I'm not sure if this is even an educated suggestion or not, but you could try the Display settings. Right-click on your desktop (not on an icon) and select Properties... In the Appearance tab, click the Advanced button. Try selecting different things in the Items dropdown box that have font properties and see if they're set to italic.
In the display Properties> Select Active Title Bar under the "Item menu" > Font: "MS Sans Serif" and make sure the "/" box is not clicked or selected. (It's nect to the "B" to the right of Color option.