Dear Friends,

I had installed Office 2007 in my system. After that I installed the trial version of Office 2013 in my system. There are so many new features in this version. Really great one. You can also try installing the trial version of Office 2013 in your system by clicking on the below image:
 

Try Office - 2013 - Trial Version

This article is to share with you one issue which i faced with this. Once I uninstalled 2013 then in Excel Macro, wherever I was using Excel.Application Library, It started throwing the below error:
 
Automation error. Library not registered
 

How To fix this:

You need to delete the below Registry Key from the Local Machine. Follow the below step to fix this issue:

Step 1. Go to Run Prompt and Type “regedit” and click ok
Step 2. Expand HKEY_LOCAL_MACHINE
Step 3. Expand Classes
Step 4. Expand TypLib
Step 5. Expand 00020813-0000-0000-C000-000000000046
Step 6. Select 1.8
Step 7. Right Click on 1.8 and Delete this.

Here you are done.