Moodle server down Apache error Forbidden permission to root on server

I was contacted by one of my customers on one of my moodle servers today.  He said the site was down.  When I browser his site, I was greeted with an Apache error message

Forbidden.  You do not have permission to access the / on the server.

Immediatly the blood pressure starts to raise.

These are the steps I went into.

Verify which server the instance was on and then check to see if the other instances on this server were doing the same thing.  Yes, they were.

Remote into the server and try restarting the Apache service or all the services.  I was able to remote into the server and give a restart the server command.  This would not only restart the services (Apache, MySQL and PHP) but would clear the memory of the Windows 2008 server (in case there was something in its memory causing a problem).  I waited about a minute and tried remotting into the server again, but could not.  I tried my other computer and was greeted with the same message.  Blood pressure rising.

I got up and went down the hall to the network guys who are the keepers of the servers.  I had one of them check the moodle server in question and he said it was up and that I was logged into it.  I asked him to reboot the server again, which would kill my login session.  He did this and I returned to my area and waited a couple  minutes.  I remoted into the server and verified that WAMP was up.  I browsed to one of the moodle instances on the server and the site came up.  I tried logging in and it timed out initially.  I tried again a couple minutes later and things seems to be back in order....

What happened?

Whey was Apache erroring with this message?  

Why, after restarting the server, was my session still active and not letting me re-connect?

I probably should have just restarted the Apache service when I initially remoted into the server.  If the problem persisted, then try restarting MySQL and PHP.  When the site is down, I get a little panicky and go for the complete reboot, which then does not really allow me to figure out why this was happening.

Is is something in one of the moodle instances?  Could it be something in the network?  Why did only 1 of my 5 servers go down?

The checked the drive space, but was plenty of space avail.  I recall once when I was automating the DB backups, the server ran out of space to write the backup file and crashed MySQL.

So why did this happen?  I will google a bit to see if anyone else using WAMP has seen this happen.

The other thing I will do is make a copy of the httpd.conf and vhost file and save it to the desktop.  I did this for one of my servers, but I will double check those too.  Just in case Apache every crashes, I do not want to have to try to rebuild those configuration files.