Cells getting copied automatically

[MAMatheen]

Why my cell / cells (cursor / selected portion) are getting copied automatically, when clicking on customized ribbon / task-bar (anywhere not selecting the commands) & upon selecting any command from the top.
I am also trying to format the cell using the button "Format Painter" I can't, coz when I click on "Format Painter" the cell is copied automatically and the format painter doesn’t work.
I deleted all macros which I created for my use. I have unchecked all the additional add-ins installed. Still the problem is unresolved.
Please help me on this Issue.
Thanks & Regards,
Abdul Matheen Mohammed

 

[Luke M]

Does this happen for any workbook, or just one?
The cells get copied...do they get pasted somewhere? Format Painter does work by initially copying, and you select paste range.
What is in your customized ribbon?
Have you tried restarting XL?

 

[MAMatheen]

It happens to all workbook / sheets & if we open the new workbook the first cell A1 is copied automatically.
No it doesn't get pasted automatically, but if we hit enter in other selected place the values or formula gets pasted there.
Format painter doesn't work, if we click on Format Painter the selected cell / cells are getting copied.
Customized ribbon or say Tool bar.
Yes I tried restarting the Excel.