After spending all day trying all the suggestions to get past this error while trying to install PostgreSQL on Windows 7 64-bit, I finally was given one that works. The EnterpriseDB guys gave me a link to one of their pages, I entered the error msg in their search box which found this forum page which down the page a little tells you to get rid of an old erroneous "(default)" McAfee registry entry and put in another correct value. This works like a charm as I was able to get my PostgreSQl 9.x going on my Windows 7 64-bit.
http://forums.enterprisedb.com/posts/list/3040.page
http://forums.enterprisedb.com/posts/list/3040.page
