How can I fix a missing MSVCR90.dll file error?

After installing Office Home and Business 2010, SP1 and all Windows Updates, whenever I try to run Excel, I get this message...

The program can't start because MSVCR90.dll is missing from your computer.
Try reinstalling the program to fix the problem.

This problem is driving me nuts. I've repaired, uninstalled and reinstalled, used a Microsoft Office 2010 removal tool (Microsoft Fixit 50450), none of which have helped.

Only Excel doesn't work - Word, PowerPoint and Outlook are fine. I also haven't noticed any other applications with any problems. I've tried the C++ 2008 SP1 installer as you suggested, but it's made no difference.

Holding down Ctrl, or adding the command line argument -s doesn't make any difference - the error message is just the same. There don't appear to be any add-ons defined in the registry under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\14.0\Excel or HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Excel.

The MSVCR90.dll is a dynamic link library which is used by programs made in Microsoft Visual C++ 2008. The simplest way to solve the problem is to download the redistributable and install it or reinstall it if it's already installed. Office setup is supposed to do that automagically, but it seems that it's not working.

Here's a link to it.

In addition to that, you may want to download the Microsoft Visual C++ 2008 SP1 Redistributable Package. I'm not 100% sure if Windows update will automatically upgrade regular redist to SP1 version or not. I'm recommending to first get the non-SP1 version because I've heard of people who had problems is they got the SP1 version first.

If you have a 64 bit operating system installed, you should get the 64 bit versions of those downloads too. They're here and here.

Just when I thought I was going to have to wipe the computer and reinstall everything to fix the problem, I decided to uninstall applications one at a time to see if one was conflicting.

I uninstalled these apps...

• Zetafax Client Applications

• Visual Studio 2005 Tools for Office Second Edition Runtime

• Microsoft Silverlight

I then performed yet another repair on Office Home and Business 2010, rebooted and voila - Excel is working again.

I've since reinstalled Zetafax Client Applications and Microsoft Silverlight with all the latest Windows Updates and Excel is still working.

I think the conflict was with "Visual Studio 2005 Tools for Office Second Edition Runtime", though I've no idea which application installed this in the first place.

Problem solved.

This issue now appears to have been solved with a Windows Update. We encountered the same issue again with another machine. Uninstalling the apps listed here and repairing Office didn't help, but running the latest batch of updates that came out on Tuesday 14th February 2012 seems to have fixed the issue.

This error was driving me crazy. After installations and uninstallations, I realized that this issue was starting after updates from Microsoft. As soon as a specific update was installed the problems would start. I started uninstalling updates. The issue is not SP1 but a specific security update for Excel 2010. As soon as I uninstalled it, the issue was gone. If you click programs and features and then "view installed updates" you will see a security update specifically for Excel 2010. Uninstall it and everything will be good again :)