>>I have no idea what this message means, but search brings http://support.microsoft.com/kb/162797/fr
>>
>>Is it relevant?
>>
>>(In English http://support.microsoft.com/kb/162797/en )
>
>It seems the proper message would then be:
>
>"The trust relationship between this workstation and the primary domain failed."
>
>The situation we are facing is that if we install our application on a PC, having Windows 7, even if the account is administrator, the domain will forbid the application to write into the Registry in the HKLM section. We are trying to find out what is causing that at the domain level. This is new to Windows 7. There is an additional level of security. If the account is not within the domain, it works.

Don't write to registry. Use INI file instead. Craig B recently gave me a link to a really good document about Windows 7 compliance. The simple way will be to forget about registry and use INI files - that's the Windows 7 standard. I recently converted one of our apps (in VFP) from using registry to using INI.