Determine whether your computer is running a 32 bit version or 64 bit version of the windows operating system

When you install Microsoft Lync 2010 communications software, depending on your computer's operating system you will need to choose between a 32-bit version or a 64-bit version installer.

The minimum operating system requirements for Lync 2010 is Window 7, Windows Vista, or Windows XP Professional with Service Pack 3 (SP3). For more information about system requirements, see Lync Online and Online Meeting Add-in for Microsoft Lync 2010 System Requirements.

Determine the operating system bit count

• Windows 7 or Windows Vista

• Windows XP Professional

Windows 7 or Windows Vista

If you have Windows Vista or Windows 7, there are two methods to determine whether you are running a 32-bit or a 64-bit version. If one does not work, try the other.

Method 1: View System window in Control Panel

1. Click Start, type system in the search box, and then click System in the Control Panel list.

2. The operating system is displayed as follows:

3. For a 64-bit version operating system: 64-bit Operating System appears for the System type under System.

4. For a 32-bit version operating system: 32-bit Operating System appears for the System type under System.

Method 2: View System Information window

1. Click Start, type system in the search box, and then click System Information in the Programs list.

2. When System Summary is selected in the navigation pane, the operating system is displayed as follows:

3. For a 64-bit version operating system: X64-based PC appears for the System Type under Item.

4. For a 32-bit version operating system: X86-based PC appears for the System Type under Item.

Windows XP Professional

If you have Windows XP, there are two methods to determine whether you are running a 32-bit or a 64-bit version. If one does not work, try the other.

Method 1: View System Properties in Control Panel

1. Click Start, and then click Run.

2. Type sysdm.cpl, and then click OK.

3. Click the General tab. The operating system is displayed as follows:

4. For a 64-bit version operating system: Windows XP Professional x64 Edition Version < Year> appears under System.

5. For a 32-bit version operating system: Windows XP Professional Version < Year> appears under System.

Method 2: View System Information window

1. Click Start, and then click Run.

2. Type winmsd.exe, and then click OK.

3. When System Summary is selected in the navigation pane, locate Processor under Item in the details pane. Note the value.

4. If the value that corresponds to Processor starts with x86, the computer is running a 32-bit version of Windows.

5. If the value that corresponds to Processor starts with ia64 or AMD64, the computer is running a 64-bit version of Windows.