Here is my fix for this problem:
I’m using Win 7 64bit and Office 2007
Run program “dcomcnfg -32“. ( You cant find the word and excel components if it runs under 64bit)
Go to “Console Root/Component Services/Computer/My Computer/DCOM Config/”
Look up Microsoft Word and Excel and choose properties.
Go to Security and select “Customize” under “Configuration Permissions. (If needed you might want to change the other permissions as well, but I didn’t need to)
Add “IIS_IUSRS” and give it “Full Control”.
Now go to “Identity” and select “The interactive user”.
Do not forget to press “OK” when done. 😀
I Hope this helps you with your problem and also the rest who gets here and read this.