The requested operation has failed!

The requested operation has failed!
That's all I get when starting Apache.

For years I had Apache installed on my Windows XP Home, in combination with
PHP and MySQl..
Twice I installed an update, and that went pretty fast and I had things
running well configured within a few hours.
They say, never change a winning horse, but with the comming of ADSL I
decided to update the whole lot to the latest versions.
Poor me...

I set up Apache /2.0.49 [Win32] and that went pretty fast. It worked fine
and offered me al the .html files I started browsing.
Then I added PHP in C:\PHP
and added the following to the C:\Program Files\Apache
Group\Apache2\conf\httpd.conf

ScriptAlias /php/ "C:/PHP/"
...
AddType application/x-httpd-php .php .php3 .phtml
AddType application/x-httpd-php-source .phps
...
Action application/x-httpd-php "/php/php.exe"

From that moment on I only get the message mentioned in the first line of
this mail from Apache.
In the service monitor the dot left of the service Apache2 stays alarmingly
red.
Nothing is written in the Apache log files.

I have been looking on many Apache / PHP related sites now for a clue for
days, painstakingly checked my ini files,
but it is slowly driving me mad.
Please help me...

What did I do wrong...

Peter Crom