Since Aspose.Editor was developed long before the Win7 and IE8 we didn’t test it in such environment and doesn’t guarantee that it will work in Win7 + IE8. Theoretically there’s no reason preventing Aspose.Editor to work in Win7+IE8, and we know some customers succeeded to run it within IE8.
I’d like to suggest you to check the security settings of IE8, and .NET framework.
Possible reasons are:
Incorrect .NET version (Aspose.Editor needs 1.1 or 2.0)
Incorrect .NET security configuration (please look at security configuration topic in product documentation)
Incorrect IE8 settings which block AcrtiveX/.NET controls.