What files to save before a upgrade

Cognos BI 10.2.2
Microsoft Windows 2012 R2 Server
What files should I save in a backup folder, before I apply a fix pack or do a upgrade of a Cognos BI 10.2.x installation?
If you have done advance tuning to the Cognos functions then this files are maybe updated;

You should keep a copy of the original file you change with the ending .org like system.xml.org. Then you should copy your updated file with a ending like .ibm – then if the fix pack overwrites your system.xml file you have a copy of the file in system.xml.ibm, that you can copy back after the updated.

If you have done report customization then there is this files you need to make a copy off;

GlobalReportStyles.css 8.x styles Classes that were used in IBM Cognos 8 BI
GlobalReportStyles_none.css Simplified styles Classes that have minimal styling defined, useful for financial reports
GlobalReportStyles_1.css 1.x styles Classes that were used in IBM Cognos ReportNet
GlobalReportStyles_10.css 10.x styles Classes in the default style sheet for IBM Cognos 10 BI

They are in this folders

<c10_install>\bin\ The file in this location is used by Report Server for PDF and Microsoft Excel spreadsheet software outputs.
<c10_install>\webcontent\schemas\ The file in this location is used by IBM Cognos Viewer for HTML output.
<c10_install>\reportstyles\ The file in this location is not currently used.
<c10_install>\webcontent\reportstyles\ The file in this location is used by Report Studio.

Then you also may backup this files if you made changes there:

You should also export a unencrypted cogstartup.xml file from each servers Cognos Configuration. Save this file in a separate folder like d:\temp\cogstartup backup 20171124.xml

Include the date, when you saved the file, in the filename.

More information: