Well...I have the same problem with the HM not finding the postgres ( cannot locate 127.0.0.1 etc)
for now I have Windows ultimate 7 x64 ... but a first glance it is similar to Windows Vista x64 (from the viewpoint of programs)...and I have postgres 8.4 that doesn`t appear to have any difference from 8.3 (at least for this problem)
the odd thing is that a new user account with name Postgres and my password appears in the Windows Log Screen... (cannot see this account in Control Panel...and this way I can`t remove this uselles account) Minor Problem (anyone have an idea?)
well...I try all the things that I see here in the FAQs and posts...none of then works for me...
In my case the service cannot get started...by any way (PGAdmin, HM, or Services (Control Panel > System and Security > Adminstrative Tools > Services )
There I see that "PostgresSQL Server 8.4" , have a field named "Log On As" .\postgres (in my thoughts this service will only start in that other user account) but when I change this field to Local Service (right click in "PostgresSQL Server 8.4", Properties, go to the tab Log On and choose Local System account ) , suddenly the service started and my problem was solved...
2 days of my grind was lost but its ok! Hope another one have a better luck! (moderators...include this at FAQs)
by the way I have my Windows Firewall and Windows Defender disabled, and my Anti Virus uninstalled, and my HOSTS file edited like said in the forums... but I guess I just needed that step above.