This problem has been reported by several people, like elog:551
So far I could not solve it. On the computers at our lab it works find so I cannot reproduce and fix the problem. One suspicion I have is that the underlying libusb library needs to be updated. You can try to install the newest version from their website at http://libusb.info/, but I haven't tried it myself.
when I change a new computer(win7,64bit),I meet a problem that the drscl app cannot found the board! It shows"USB successfully scanned,but no boards found",but the drsosc runs well . when I connect to other win7*64bits computer,only one of them runs property! Is there any driver else I need to install?