After reboot some dll files are missing preventing PG to start

Dear PostgreSQL hackers,

Postgresql version: 8.4.16
System: Windows 7 Pro x86_64

from time to time, on several different machines (sharing the same
Windows 7 image), I've noticed that PostgreSQL and other postgresql
related binaries (psql.exe for example) refuse to start after having
rebooted the computer.
There is nothing in the logs.

I tracked down the issue to 2 suddenly missing files:
- libintl-8.dll
- gssapi32.dll
When those 2 files are copied from a healthy computer to the ill one,
then it works.

It seems related to the way Windows 7 restarts/halts. I cannot tell with
extreme guarantee that it happens when the computer starts from a cold
boot but for sure I've had it plenty of times right after reboot.

However it does not happen at every reboot and I cannot predict if it is
going to happen or not.

I believe this matter is critical. As the service is down it is not
possible to backup the databases and as the only way to fix the issue is
to reinstall (except the method above) then the databases are deleted.

Do you have any inputs on this? How could I help you to fix it?

Thanks in advance for your interest on my case,
Grégory.