I had this same issue, and I have fixed it. I found out from looking at the Event Viewer, I saw the following error:
Activation context generation failed for " C:\Program Files (x86)\Microsoft Office\Office14\OUTLOOK.EXE.Manifest" . Dependent Assembly Microsoft.VC90.CRT,processorArchitecture=" x86" ,publicKeyToken=" 1fc8b3b9a1e18e3b" ,type=" win32" ,version=" 9.0.30729.1" could not be found. Please use sxstrace.exe for detailed diagnosis.
You can find this assembly module, which is distributed normally with Visual Studio 2008 SP1. If you do not have VS 2008 SP1 installed, then I am assuming that you will see this error. Also, if you are running a 64-bit OS (I am running Windows Vista, not sure if the same thing will occur with Windows 7) and trying to install Microsoft Office 2010 (a 32-bit version was only available for me at a discount - although I would prefer the 64-bit version).
Download the small package, install it, and try again. Here is the link for the VC90.CRT module you need: http://www.microsoft.com/downloads/en/details.aspx?FamilyID=a5c84275-3b97-4ab7-a40d-3802b2af5fc2&displaylang=en