Can't open any Office 2013 program and "There was a problem sending the command to th

[LRAT]

Can't open any Office 2013 program and "There was a problem sending the command to the program"

Hi,
I purchased Office 2013 sometime at the start of last year, Order#: CNL61123XXXX, program code A65117XXXX (If you want to know the exact number that PM me, I just want to show it's a ligit purchase).


It has been working flawlessly for nearly a year until a couple of days ago I couldn't open any office documents. Whenever I click on a document (Whether its Excel, Word, Powerpoint, etc), I receive the message "There was a problem sending the command to the program".
When I try to open Word, Excel, etc. I click on it and nothing happens. No screens open up, no faults, just nothing.
I need Excel for work purposes all the time and this is very annoying. All my files open up on another computer running Office 2003 and 2010, no problems, nothing corrupt.
When I reboot in safe mode it behaves exactly the same, it doesn't make a difference.
I decided to uninstall Office 2013 and re-install Office 2010 or 2007 as I have purchased previous versions as well, but, I can't uninstall Office 2013 and the system refuse to install Office 2010 on my PC.
I am in a real trouble here. I have searched the internet and I have checked all the available options, such as: Uncheck "Run as administrator" under Properties.
Most fixes are based on the fact that people will be able to open the Excel program but can't open files. I can't even open the program, not even when I run it as Excel /Safe.
I have installed all latest updates Windows 7 and Office related. This didn't help either.
Could you please give me some indication what needs to be done to correct this?
I am running office on a HP PavilionDV6 laptop and this has all the latest updates installed as well. No problems with no other programs and couldn't find any malware, viruses using MawareBytes, Avira, McAfee, etc.
The other thing is when I purchased Office 2007 and Office 2010 I could download a .exe file and store this on my PC. When I purchased Office 2013 it installed on my PC but didn't leave any .exe files. From memory the complete download was just over 1 GB. That's the reason why I want to roll back to 2010 as I can't find any .exe file.
Thanks,

Luc

PS: I am in Antarctica and we've got limited bandwidth, so, please no links to hefty downloads.