Help remove cfw from psp 2001

Ive just bought a PSP 2001 from eBay. Everything seems to work until i wanted to log into my PSN account and then it asks to connect to the internet which i tried to do but my wifi isnt supported (i have verizon fios). so i tried to do an update through the computer and the current update is 6.61. when i tried to install the update i get "The system software of your PSP system is 9.90. there is no need to update". i dont know anything about cfw and i think thats what i have on there. the cfw is "5.50 Prome-4" is there any way i can remove it?