Please help...product detail pages will not load, gives 500 error

I am still very knew to zen cart and have no clue about php. I have been working on my store and up until today it worked fine. Now I can not see any of my product detail pages. From my store or from my admin, I get "Bad Response From Server or 500 error".

I don't know if anyone can help but I have spent the last 24 hours reading through forums and FAQ's and have not found an answer to help.

my store is http://raynegsc.com/Shop/

You can see by going there and clicking on any product they all do the same. It does the same thing when I try to edit product details in the admin section to.

Please can anyone help me.....

A 500 error is not a zencart fault... 500 relates to the server.

Go into your C-Panel at your webhost, and view the error log. That will give an indication of where the poblem lies.

I thought so as well, but when I ask my hosting company they said it was with zen cart and it's ability to acess the database. I seem to have no error logs. None with my hosting and none with my debugging for zencart.

I am on a windows server and from what I was told, it doesn't log errors. I checked just to make sure and no where in my control panels does it have the options for error logs.

I have made changes to these zen cart files

english.php - to make changes to the page titles of page 2, 3 and 4
tpl_footer.php - to add a custom footer
information.php - to move page 2, 3, and 4 from more information to the information box.

Added add-ons - Easy populate.

Could any of those have caused the error maybe or corrupted something I may not be thinking of. I have replaced the entrie folder modules/pages/product_info. I have replaced the root htaccess.

My database is mysql....I have no idea of what to look for there to see if there is a problem.

It does the 500 error also when I use easy populate and loaded the products. Once it uploaded it would jump to the 500 error page, but when I checked the store the items were added....some information all jumbled but they did add. Don't know if that help point out the problem, but hopefully.

I am on a windows server

Why are you using a Windows box? Move to a Unix server.