Excel 2007 : my excel doesn't work properly in my computer

Hi,

I'm using excel 2007. I don't really know when the problem started. But my excel doesn't work properly.
Here are the ff. problems I encounter:

1.) I can't paste the formula, only the value will appear every time I try to copy a formula from one cell to another.
2.) I tried copying selected cells, which includes the borders, font style/color, wrap text and merge cells,
but when I paste it to another sheet, or same sheet, it doesn't appear to be exactly as the one I copied.
No borders, no font style/color... no everything!
3.) I also tried copying my files to the USB and opened it to another computer and it's working properly!

I really don't know how to fix the problem..please help me..

dont know if this will help
http://www.excelforum.com/excel-gene...-in-excel.html