Method 1
Set the permission for the Everyone group of the registry subkeys that are listed in the error message to Full Control. Use the 'Fix It' and follow the steps provided in the KB article
For more information how to let Microsoft Fix it for you , click the following article number to view the article in the Microsoft Knowledge Base:
313222  (http://support.microsoft.com/kb/313222/ ) How do I restore security settings to the default settings?

Method 2
Disable the third-party application. For example, to disable WebRoot Spysweeper, follow these steps:
Right-click the WebRoot Spysweeper icon that is located in the notification area, at the far right of the taskbar.
Left-click the Shut Down option.
In the Office installation Error 1406 dialog box, click Retry.
When the Office setup is completed, restart the computer, and then re-enable WebRoot Spysweeper.

Method 3
Take the system into a "clean boot" state, and then run Office setup. This disables the third-party applications. The third-party application that is denying access to the registry subkey can no longer deny access.

For more information about how to take the system into a "clean boot" state, click the following article number to view the article in the Microsoft Knowledge Base:
310353  (http://support.microsoft.com/kb/310353/ ) How to configure Windows XP to start in a "clean boot" state

For more information about how to take the system into a "clean boot" state, click the following article number to view the article in the Microsoft Knowledge Base:
950093  (http://support.microsoft.com/kb/950093/ ) How to use the System Configuration utility to troubleshoot configuration errors in Windows Vista

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.

Method 4
Some activation problems indicate that the license file is corrupted. If the license file is corrupted, you cannot resolve the problem by removing and then reinstalling the Office product. The license file is not removed when you remove the Office product. Additionally, the license file is not overwritten when you reinstall the Office product. If the license file is corrupted, use one of the following methods to delete the license file.

Note Method 4 applies only to Office 2007, Office 2003 and Office XP. Office 2010 does not use the OPA licensing file.
Fix it for me
To delete the corrupted license file automatically, click the Fix it button or link. Click Run in the File Download dialog box, and then follow the steps in the Fix it wizard.

Fix this problem
Microsoft Fix it 50302

Note This wizard may be in English only; however, the automatic fix also works for other language versions of Windows.

Note If you are not on the computer that has the problem, you can save the automatic fix to a flash drive or to a CD, and then you can run it on the computer that has the problem.
Let me Fix it myself
To resolve this problem yourself, follow these steps.

For Windows XP or Windows Server 2003
Log on to the computer by using an Administrator user account.
Start Microsoft Windows Explorer.
On the Tools menu, click Folder Options.
Click the View tab.
Under Hidden files and folders, click Show hidden files and folders.
Click to clear the Hide extensions for known file types check box, and then click OK.
Open the following folder: C:\Documents and Settings\All Users\Application Data\Microsoft\Office\Data\
If you are running Office 2007, right-click Opa12.dat, and then click Properties. If you are running Office 2003, right-click Opa11.dat, and then click Properties. If you are running Office XP, right-click Data.dat, and then click Properties.
Click the Security tab.
Click Advanced.
Click the Permissions tab.
Click to select Everyone in the Permission entries list, and then click Edit.
Click to select the Full Control check box.
Click OK three times. If these steps do not resolve this issue, delete the Opa11.dat file or the Data.dat file from the following folder, and then restart an Office 2003 program or an Office XP program:
C:\Documents and Settings\All Users\Application Data\Microsoft\Office\Data
For Windows Vista or Windows 7
Log on to the computer by using an Administrator user account.
Start Microsoft Windows Explorer.
On the Organize menu, click Folder and search options.
Click the View tab.
Under Hidden files and folders, click Show hidden files, folders, and drives.
Click to clear the Hide extensions for known file types check box.
Click to clear the Hide protected operating system file (Recommended) check box, and then click OK.
On the Warning dialog box, click Yes.
Open the following folder: C:\Users\All Users\Microsoft\Office\Data\
If you are running Office 2007, right-click Opa12.dat or if you are running Office 2003, right-click Data.dat, and then click Properties.
Click the Security tab.
Click Advanced.
Click the Permissions tab.
Click to select Everyone in the Permission entries list, and then click Edit.
Click to select the Full Control check box.
Click OK four times. If these steps do not resolve this issue, delete the Opa12.dat, the Opa11.dat file or the Data.dat file from the following folder, and then restart an Office 2007 program, an Office 2003 program or an Office XP program
C:\Users\All Users\Microsoft\Office\Data