[SOLVED]Backup & Recovery 10 Installation fails

Hello ! I have a problem when installing Acronis Backup & Recovery 10 on a XP SP3 computer: the installation fails when trying to install the first package: the Agent.

I give you a screenshot of the error (in french)

The code error is 013795853

Suberror messages are:

- Cannot get IDs: error occurred while checking integrity of the task.
- Failed to check task integrity: error occurred while enumerating the task.
- Scheduling error.
- The RPC server is too busy to complete this operation.

It seems to be the same error than in this old post http://forum.acronis.com/forum/14766.

Thank you for helping me !

PS: sorry for my english, I'm french ;)