Open Regedit and navigate to the following key:
Check the REG_DWORD entries: NT AUTHORITY\NETWORK SERVICE, LOCAL SERVICE, NetworkService, etc., and their equivalent in your language (e.g. Servicio de red, SERVICIO LOCAL). If any of the users listed has a value of 0, set it to 1. Restart the Cryptographic Services by issuing the following commands:
net stop cryptsvc
net start cryptsvc
According to Microsoft, this problem can occur if any COM applications or COM+ applications cannot access the COM+ catalog files. The application cannot access the COM+ catalog files because the default permissions on the COM+ catalog directory and files have been changed from the default settings.
If this problem appeared after installing Yukon April CTP (SQL Server 2005), the see the link to "How to fix a problem with Windows backup and the Volume Shadow Service after installing Yukon April CTP" for information on fixing the problem.