Just downloaded and installed the official version. The same problems encountered with RC3 occured. See
After taking some 20 minutes with the HDD led fullly on (meanwhile JAVA updated, is this part of the install??) and unable to cancel the install (cancel button greyed out) I killed the install from the task manager.
Reinstalling again brought up the same error 1706 screen but this time the installation completed after installing a signed driver.