This is likely because your root DotNetNuke folder is probably too far down the directory tree on your computer.  I suspect that it's probably inside c:\documents and settings\username\my documents\someplace in your documents folder\....     You will want to host the site directly off the c:\ drive in a folder like c:\DNN<SITENAME>\files so thath you don't run into the path name is too long problem.

Er is een kritieke fout opgetreden.
The specified path, file name, or both are too long. The fully qualified file name must be less than 260 characters, and the directory name must be less than 248 characters.

I did some extended testing on this one this weekend.

I took the standard Store core module and installed this in both the version DNN 4.3.5 and 4.4.0.

The DNN 4.4.0 is installed in "INSTALL" mode, the DNN 4.3.5 is installed in the "SOURCE" mode.

I did the same with the WW_Store module from Allan. So I ende up with two versions DNN and two store webshops in every DNN version.

I'm running these DNN's in a MSDE 2000 database with Windows 2000 server.

I get this error in all cases when I want to check out.