HELP: PHP, Apache, Win '98...what's wrong?

Firstly, I won't profess to know all that much about how computers really work, and to know all the technical words about what things are...here in England, IT isn't taught all that well, and I've just had to teach myself instead (I'm 18).

OK. I'm trying to find out how PHP works so that I can try and make some dynamic pages, with more flexibility than using simple SSI tags.

I design all my sites on my Win '98 machine, and have for about half a year been using Apache on it so that I can see how the pages look, and test server-side scripts such as PHP before uploading to the web server.

I've downloaded the main PHP working scripts from DevShed (global.php3 etc) to see if I can get them to work, and see what everything does in them so that I can understand what's going on, and how I can use such code for my own sites.

However...I think there must be some problem with my Apache or Win '98 configuration somewhere. In trying to run an index.php3 file with the following code:

<?require( '/data/php/templates/devshed/category.php3');
$categoryID=8;
getCategory();
?>

I get a message saying:

Fatal error: Failed opening required '/data/php/templates/devshed/category.php3' in C:usretchtdocsdevshedindex.php3 on line 1

In other words, it seems as though instead of trying to find the category.php3 file inside http://devshed/data/php/templates/d.../category.php3, it's looking in C:usretchtdocsdevshedcategory.php3 - outside of the server files.

Without knowing all the technical wordings to use hear, I hope you've understood what I'm trying to get at. If not, I'll try and explain it further.

If you can help me here that really would be great. Also, if you can recommend a good book so that I can learn a little more about what I'm talking about, then that would be even better!

Jake
jakeg@lineone.net