pmb software

i have windows 7 and my pmb software cannot detect dvd rw drive. i burn dvd before this problem create and after some changes pmb cannot detect dvdrw drive. May be by mistake i change 32 bit to 64 bit. So pls tell me how to change 64 bit to 32 bit

Most newer 32bit software will run under Win 7 64-bit. However it is possible there are no 64bit drivers to support your dvd+-rw.

Unfortunately there is no easy migration from 32 to 64bit nor from 64 to 32bit and you want to try 32bit; I'm afraid you must reinstall.