Remove Oracle 10g manually from windows 8.1

Step - 1 : Open Registry Editor (regedit.exe).

Step - 2 : Remove Oracle key from Services folder.

Step - 3 : Remove Oracle key from Wow6432Node folder.

Step - 4 : Restart your PC and remove folder where Oracle is installed. Oracle 10g is generally installed with the name ORACLE. 

Step - 5 : Remove oracle folder from Program Files or Program Files(x86) folder. 

Note : Sometimes you need not to worry about step 4 & 5. once you removed oracle registry, Oracle folder is automatically removed but it is better practice to check at least once whether oracle folder is deleted automatically or not.