Excel is loading very slow...

Hi everyone!
I have an issue with Excel 2013 from Office 2013 ProPlus.
Excel is loading for like 1 minute. When launching it from shortcut, or by clicking on file. Few days ago I had same problem, and when I wanted to launch from a file an error occurred: 
"There was a problem sending command to a software."

After searching in the net for possible solution, I:
-turned off all add-ins
-checked if DDE is switched off

But the issue remained.
I reinstalled software, after installing it once again, problem remained.

After wiping out Excel Registry, problem was fixed.
Today I launch excel and it's back... But without this error.
What should I do?
thx