A "Request For Permission to Use a Key" dialog box appears every time that you send an e-mail message in Outlook 2007

After you apply this hotfix, you can set registry entries to configure the number of digital IDs that an application uses. Additionaly, you can set the length of time that the application caches the digital IDs. For more information, see the "Registry information" section.

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

To apply this hotfix, you must be running Windows 7 or Windows Server 2008 R2.

Registry information

This section contains information about how to configure the number of digital IDs that an application uses, and the length of time that the application caches the digital IDs.

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

322756 How to back up and restore the registry in Windows

To configure the number of digital IDs that Windows 7 and Windows Server 2008 R2 can cache in an application, follow these steps:

1. Click Start, type regedit in the Search programs and files box, and then press ENTER.
2. Locate and then click the following registry subkey:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Cryptography
3. On the Edit menu, point to New, and then click DWORD Value.
4. Type PrivKeyCacheMaxItems to name the new entry, and then press ENTER.
5. Right-click PrivKeyCacheMaxItems, and then click Modify.
6. Click Decimal under Base.
7. In the Value data box, type the maximum number of digital IDs that Windows can cache in an application, and then click OK.
   
   Note If you do not want Windows to cache digital IDs, type 0 in the Value data box.
8. Exit Registry Editor.
   

To change the length of time that Windows 7 and Windows Server 2008 R2 cache digital IDs in an application, follow these steps:

1. Click Start, type regedit in the Search programs and files box, and then press ENTER.
2. Locate and then click the following registry subkey:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Cryptography
3. On the Edit menu, point to New, and then click DWORD Value.
4. Type PrivateKeyLifetimeSeconds to name the new entry, and then press ENTER.
5. Right-click PrivateKeyLifetimeSeconds, and then click Modify.
6. Click Decimal under Base.
7. In the Value data box, type the length of time in seconds that you want Windows to cache digital IDs in an application, and then click OK. For example, if you type 2,592,000, Windows caches digital IDs for 30 days.
8. Exit Registry Editor.
   

To change the interval at which Windows removes the outdated keys, follow these steps:

1. Click Start, type regedit in the Search programs and files box, and then press ENTER.
2. Locate and then click the following registry subkey:
   HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Cryptography
3. On the Edit menu, point to New, and then click DWORD Value.
4. Type PrivKeyCachePurgeIntervalSeconds to name the new entry, and then press ENTER.
5. Right-click PrivKeyCachePurgeIntervalSeconds, and then click Modify.
   
6. Click Decimal under Base.
7. In the Value data box, type the time interval in seconds for Windows to remove the outdated keys, and then click OK. For example, if you type 2,592,000, Windows removes the outdated keys every 30 days.
   
   
   Note By default, the value is 86,400. Therefore, if you do not change this value, Windows removes the outdated keys every single day.
   
8. Exit Registry Editor.

Restart requirement

You do not have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

The global version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.

Windows 7 and Windows Server 2008 R2 file information notes

Important Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both of these operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.

• The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 R2 and for Windows 7" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintaining the state of the updated component. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

For all supported x86-based versions of Windows 7

For all supported x64-based versions of Windows 7 and of Windows Server 2008 R2

For all supported IA-64-based versions of Windows Server 2008 R2