Let's say you are having data as given below and you want to highlight all the cells in columns after first column where cell values are different.
B1 is not different from A1 where C1 is different from A1, hence C1 will be highlighted.
In row 2 both B2 and C2 will highlighted and so on.
1. Select the required range. In above case, select A1:C8.
2. ALT+EGSW and Enter (ALT+EGS opens Go to Special and W selects "Row Difference")
And you will have your results.
ALT+EGS to disply
Note - For ROW CELLS, select Column Difference i.e. ALT+EGSM and you get following results (I have changed data set to illustrate the concept. Here comparison is done with first row for following rows -