encryption?

hello
plz i got a big problem
i did encrypted some iimportant files in my pc….
then i found my operatig system(xp) need to unistall it..then i had formatted everything except these files.. so i put a new windows xp then am trying to to access these files tells me “ACCESS DENIED” then i tried to my self in permission it added me but it appear to me the same error
by the way am the admin in this pc
thx

by the way am the dmin in my pc