Microsoft Office Home and Business 2010 cannot verify the license for this product

I've seen many threads about this already, and a couple potential solutions. Unfortunately, none of them have worked so far.

I have Microsoft Office Home and Business 2010. It was installed from Dell when we purchased them. It's a full licensed version. Yesterday morning I received 3 phone calls with users having the same issue. When they try to launch any of the office products they get "Microsoft Office Home and Business 2010 cannot verify the  license for this product".

I've uninstalled, reinstalled, repaired, reentered the product key. No success. I've tried running cscript ospp.vbs /act, and also not working.

Any chance anyone can assist?