Using OCT tool, I have upgraded Office 2010 software to Office 2013 on end users workstation remotely. After upgrading the software when the user right clicks on the desktop and chooses 'New', 'Microsoft Excel worksheet', it creates a file on the desktop, but, when trying to open it, it returns with the below error:

"Excel cannot open the file 'New Microsoft Excel Worksheet.xlsx because the format or file extension is not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file."

Appropriate solution will be highly appreciated.

Thanks & regards,

Hi Kiran2015,

According to your description, you upgraded your excel and cant open the excel file.

This might be a file associations problem.  Try to this method: Right click the file- Click Open with- Click Choose a program- Check Always use the program to open this type of file- Scroll down the Excel and select it and click OK.

If excel isn't in the list select 'Browse' and navigate the excel.exe, if you used the default installation it will be something like:

C:\Program Files\Microsoft Office\Office15\EXCEL.EXE

When you find it, highlight it and click OK.

And if this method doesnt, with your error message this problem has been confirmed to be caused by malware on the affected machine. There are now two known variants of malware which causes this problem: Win32/Crilock.A and Win32/Buma!rts. They have both been identified as a new family of ransomware.

In order to clean your machine, run Microsoft Safety Scanner (http://www.microsoft.com/security/scanner/en-us/default.aspx). If infected, Safety Scanner should clean the virus from the system, however it will not repair corrupted files. You will still need to restore those from a backup. A detailed analysis of affected files submitted to Microsoft for investigation has revealed the files are encrypted with a private and public key. The files cannot be recovered without the private key, which is more than likely held by the attacker. The premise of ransomware is such that if a person pays the ransom the key is provided to "unlock" the files.

You can refer to this link:

http://blogs.technet.com/b/the_microsoft_excel_support_team_blog/archive/2013/09/07/quot-cannot-open-the-file-because-the-file-format-or-extension-is-invalid-quot-opening-office-files.aspx

Hope its helpful.

Regards,