You may just need to reinstall the C++ 2010 bits
32Bit: Microsoft Visual C++ 2010 SP1 Redistributable Package (x86)
http://www.microsoft.com/de-de/download/details.aspx?id=8328
64Bit: Microsoft Visual C++ 2010 SP1 Redistributable Package (x64)
http://www.microsoft.com/en-us/download/details.aspx?id=13523
Any other issues with excel should be directed here
https://social.msdn.microsoft.com/forums/en-us/home?forum=exceldev
https://answers.microsoft.com/en-us/msoffice/forum/msoffice_excel-msoffice_custom
(please don't forget to mark helpful replies as answer)