So this is simple sitecore patching tip, but one of the most common used ones.

Every time you install a fresh Sitecore solution, you would need to change the dataFolder setting in Sitecore, to match where the solution is installed. This on of course only needed if you have your datafolder outside of the webside folder. The patching file would look like the following

<configuration xmlns:patch="">
        <sc.variable name="dataFolder">
            <patch:attribute name="value">patch to new datafolder</patch:attribute>

The above is provided by Sitecore by default in an installation, in the /website/App_Config/Include/datafolder.config.example file. Simply remove the .example extension and change the value in the file.