Massive Problems on Installing

[Newb]

Hi!

I just tried to install the shop and got a whole bunch of problems. I got this redeclaration of clear_parse() error and fixed it (removed function).
Now I got Warnings in the admin:

Notice: Undefined variable: tpl in C:\Inetpub\wwwroot\ig_shop\admin\admin-catalog-product.php on line 930

Notice: Use of undefined constant return_urls - assumed 'return_urls' in C:\Inetpub\wwwroot\ig_shop\admin\session_variables .php on line 11

Notice: Use of undefined constant return_type - assumed 'return_type' in C:\Inetpub\wwwroot\ig_shop\admin\session_variables .php on line 12

Notice: Use of undefined constant return_urls - assumed 'return_urls' in C:\Inetpub\wwwroot\ig_shop\admin\session_variables .php on line 13

Notice: Use of undefined constant return_type - assumed 'return_type' in C:\Inetpub\wwwroot\ig_shop\admin\session_variables .php on line 14

Notice: Undefined property: list in C:\Inetpub\wwwroot\ig_shop\admin\class.FastTemplat e.php on line 450

Notice: Undefined variable: where in C:\Inetpub\wwwroot\ig_shop\admin\admin-catalog-product.php on line 104

The List of Warnings continue (~100) and somewhere in between the page is being build. Anyone got (and fixed) this problem?

I use WinXP pro with PHP 4.3.6 installed.

Thanks in advance
Newb