Exchange Server 2013 SP1 Standard: Installation failing can't progress

I'm trying to install Exchange Server 2013 and I keep getting this error and I am unable to progress, I can't find any support on the issue and frankly I don't want to/can't afford to spend $500 to ask Microsoft for technical support (what kind of racket do they think they're running?).

The error message:

Error:
The following error was generated when "$error.Clear();
          New-PushNotificationsVirtualDirectory -Role Mailbox -DomainController $RoleDomainController;" was run: "The Active Directory object for virtual directory 'IIS://SVR02.OFFICE.local/W3SVC/24/ROOT/PushNotifications' on 'SVR02' could not be created. This might be because the object already exists in Active Directory. Remove the object from Active Directory, then re-create it.".

Yet, I see no PushNotifications virtual directory or anything remotely related to that on IIS or in the inetpub folders and files. If I try to resume the set-up after this error I get:

Error:
The following error was generated when "$error.Clear();
          New-PushNotificationsVirtualDirectory -Role Mailbox -DomainController $RoleDomainController;" was run: "The AD configuration for virtual directory 'PushNotifications' already exists in 'CN=PushNotifications (Exchange Back End),CN=HTTP,CN=Protocols,CN=SVR02,CN=Servers,CN=Exchange Administrative Group (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=OFFICE,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=OFFICE,DC=local', please remove this AD configuration manually.
Parameter name: VirtualDirectoryName".