The desktop of my computer suddenly showed my icons and lettering in very large font, and everything is kind of fuzzy. I checked the to see if It was changed in appearance and themes and it is normal. Is this a virus.

WallyHelps

Did the resolution of your desktop get changed?
On the desktop, right-click and select Properties (you were already there to check the themes). Click on the Settings tab, and on the left there is a Screen Resolution slider. If it has room to move to the right, try that.

Good Luck,
WallyH