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When you try to log on to Microsoft Lync online by using Lync 2010, you receive the following message:

To sign in, additional software is required.

Download and install now?
However, when you click the link, you are directed to the MSN website instead of the download page for the software that is required to log on to Lync online (Microsoft Online Services Sign-in Assistant).

Note This issue occurs when you have a non-English system locale on the computer that is running Lync 2010.


To fix this problem, install the following cumulative update:

2467763 Description of the cumulative update package for Lync 2010: January 2011


To work around this issue, follow these steps:

  1. Change the system locale to English (United States), and then restart the computer.

  2. Try to log on to Lync online by using Lync 2010.

  3. Download and install the Microsoft Online Services Sign-in Assistant (Msoidcli.msi).

  4. Change the system locale back to the original setting.

To change the system locale settings, follow these steps:

Windows Vista or Windows 7

  1. Click Start, and then click Control Panel.

  2. Click Clock, Language, and Regional.

  3. Click Regional and Language.

  4. Click the Administrative tab.

  5. Click Change system locale.

  6. In the Current system locale box, select the locale that you want to use and then click OK.

  7. Click OK to close the Regional and Language dialog box.

  8. Restart the computer.

Windows XP

  1. Click Start, and then click Control Panel.

  2. Click Date, Time, Language, and Regional Options.

  3. Click Regional and Language Options.

  4. Click the Advanced tab.

  5. In the Select a language to match the language version of the non-Unicode programs you want to use box, select the locale that you want to use then click OK.

  6. Restart the computer.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

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