I suspect that error code is related to validating.
If the 25 character product key on the installation is different from what is on the label it looks as if the OS has been re-installed at some point from a disk that was different from the original.
Please visit http://www.microsoft.com/genuine/ and click on the Validate Windows button then restart your computer.
If you weren't able to Validate, proceed as follows:
1. Download this diagnostic tool, saving it to your desktop: http://go.microsoft.com/fwlink/?linkid=56062
=> WinXP: Double-click on the executable to run the tool.
=> Vista & Win7: Right-click on the executable and select Run as Administrator to run the tool.
2. After running the tool, click on the Windows tab and then click on COPY (to clipboard).
NB: You may want to open a new Notepad file, paste the contents of your clipboard into it & save for future reference.
3. Begin a new thread in the following Microsoft Genuine Advantage forum and paste the results from the WGA and/or OGA Diagnostic Data tool in a detailed post:
http://social.microsoft.com/Forums/en-US/genuinevista/threads
4. A troubleshooting specialist will analyze the data and recommend an appropriate solution.
(copied from R-Dyer)