Leave it unplugged for a few weeks... but I know of no software solution. Why would you want to do this anyway?
Prey query. What level reset are we talking? For date/time reset you can hold your four prime imputs ABXY while turning the console on without a game insterted and that should clear the internal memory. ~Krelian
Hmmm... After consulting Google another alleged means to do this is to insert the WebBrowser and plug a lone VMU-less controller into port two and power-on while holding B+X. ~Krelian