Alors j'ai trouvé ce qui m'interesse et voici la facon de faire pour ceux qui ont le meme probleme
To Change the Expiration Date of Certificates That Are Issued by a Windows Server 2003 or a Windows 2000 Server Certificate Authority
To change the validity period settings for a CA, follow these steps.
Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.
1. Click Start, and then click Run.
2. In the Open box, type regedit, and then click OK.
3. Locate, and then click the following registry key:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\CertSvc\Configuration\<CAName>
4. In the right pane, double-click ValidityPeriod.
5. In the Value data box, type one of the following, and then click OK:
• Days
• Weeks
• Months
• Years
.
6. In the right pane, double-click ValidityPeriodUnits.
7. In the Value data box, type the numeric value that you want, and then click OK. For example, type 2.
8. Stop, and then restart the Certificate Services service. To do so:
a. Click Start, and then click Run.
b. In the Open box, type cmd, and then click OK.
c. At the command prompt, type the following lines. Press ENTER after each line.
net stop certsvc
net start certsvc
d. Type exit to quit Command Prompt.