It's not a permissions problem.
That's the error message I get if I try to locate the config under an already existing SASHome - do you know if it was one previously (but maybe no longer)?
The sdwpreferences.txt documented here: http://support.sas.com/kb/49/799.html
Will contain a list of the previous paths - if it's no longer used you should be able to remove it, and install there now - but a restart of the SAS Deployment Wizard may be required.