The Fairly OddParents S03E01 - Information Stupor Highway

Timmy hopes to ask Trixie Tang to the school dance, deciding to do so via e-mail, but when his parents add their own "threat-mantic" additions to his letter (and send it), Timmy wishes to venture through cyberspace to retrieve the e-mail back before it reaches Trixie's computer. While exploring the Internet, Timmy winds up in Mr. Crocker's computer, who suspects that the pink-hatted virus may be the work of Timmy's fairy godparents, and thus sends a virus of his own to use Timmy's computer as a way to spy on Cosmo and Wanda.