8.4.13 Windows Service fails to start

Folks,

Apologies for the long post but I want to put in as much detail as possible

I just upgraded from 8.4.1 to 8.4.13 on my laptop (Vista 32 bit) and the
installation seemed to go fine. However, when I try and start the
windows service I get an error message, after a minute or so, saying:

"The postgresql-8.4 - PostgreSQL Server 8.4 service on Local Computer
started and then stopped. Some services stop automatically if they are
not in use by other services or programs."

There are several postgres.exe process running and I can access the
server from the pgAdmin console and the app that I use which has a DB on
the server has no issues with connecting to the DB.

When I look in event viewer I see the following errors:

"Timed out waiting for server startup" - always

and

"Windows detected your registry file is still in use by other
applications or services. The file will be unloaded now. The
applications or services that hold your registry file may not function
properly afterwards.

DETAIL -
1 user registry handles leaked from \Registry\User\S-1-5-21-216353801-1092987170-4140225192-1001:
Process 6928 (\Device\HarddiskVolume2\Program
Files\PostgreSQL\8.4\bin\postgres.exe) has opened key
\REGISTRY\USER\S-1-5-21-216353801-1092987170-4140225192-1001\Software\Microsoft\Windows
NT\CurrentVersion" - sometimes

If I kill all the postgres.exe processes and the start a cmd prompt
logged in as the postgres user I can issue the start and stop commands
with pg_ctl with no error messages (the status command seems to confirm
the server running).

The only messages in the log file are:

2012-09-24 21:38:13 BSTLOG: database system was shut down at 2012-09-24 21:15:55 BST
2012-09-24 21:38:13 BSTFATAL: the database system is starting up
2012-09-24 21:38:13 BSTLOG: database system is ready to accept connections
2012-09-24 21:38:14 BSTLOG: autovacuum launcher started

Any clues as to why the service won't start the server properly?

Cheers,

Malcolm.