Apparently your permiissions are not set up correctly (or the App_Browsers\Form.browsers does not exist). 

Have a look in IIS to see which application pool is used by the website. The application pool is using a username and that user should have modify permissions on the App_Browsers folder.

Hi Sebastiaan,

The file App_Browsers\Form.browser is present and the premissions are set the same as I setup all my umbraco websites. 

Is 4.5.2 based on .Net framework 4.0?

Sebastiaan,

After installation the http://referentiewebsite/install/default.aspx?redir=true&url=/default.aspx install page of Umbraco was accessable. When I proceed, the error described above is generated.

Regards,

In 

Step 3/5: Validating File Permissions

the page goes blank :-)

Does it matter that I don't have IIS7 installed

I used script below, to set the folder permissions. Still the above error is shown. I'm using XP Pro with SQL server express 2008

:: Hope you enjoy this one

:: Sets up the right folder permissions for Umbraco to run

:: Inspired by http://blog.mattbrailsford.com/2010/08/01/adding-a-windows-context-menu-item-to-set-umbraco-folder-permissions/

:: from the boys at Offroadcode.com

ECHO OFF

SET which_user="%computername%\ASPNET"

ECHO ON

cacls "%CD%" /E /G %which_user%:C

cacls "%CD%\app_code" /E /G %which_user%:F

cacls "%CD%\app_browsers" /E /G %which_user%:F

cacls "%CD%\app_data" /E /G "%which_user%:C

cacls "%CD%\bin" /E /G "which_user%:R

cacls "%CD%\config" /E /G "which_user%:C

cacls "%CD%\css" /E /G "%which_user%:C

cacls "%CD%\data" /E /G "%which_user%:C

cacls "%CD%\masterpages" /E /G "%which_user%:C

cacls "%CD%\media" /E /G "%which_user%:C

cacls "%CD%\python" /E /G "%which_user%:C

cacls "%CD%\scripts" /E /G "%which_user%:C

cacls "%CD%\umbraco" /E /G "%which_user%:R

cacls "%CD%\usercontrols" /E /G "%which_user%:R

cacls "%CD%\xslt" /E /G "%which_user%:C

cacls "%CD%\web.config" /E /G "%which_user%:C

::Uncomment below if testing

::PAUSE 

Instead of

SET which_user="%computername%\ASPNET"

You could try:

SET which_user="NETWORK SERVICE"

Or:

SET which_user="%computername%\NETWORK SERVICE"

If that doesn't help, it's probably not a permissions problem.

Yes, the default download for  4.5.2 does require .net 4 installed, but you'd get errors earlier if that was the problem.

I haven't used XP for quite a while now, and hardly ever used it with Umbraco, so I don't know what the install issues would be. I hope the change in permissions helps.

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