Hi newcomer and welcome to the Tom's hardware forum.
What is ur 1st language?.
Uninstall office, reboot the rig and use ccleaner to delete all the temp files and register of office reboot the rig again and finally run the setup.exe BUT this time select custom installation and in the windows where u can select the products (word, excel, power point) select "Run all from the PC" or something like that. Wait until the installation finish reboot the rig an try again.
Thanks, Saint19! My 1st language is Portuguese (Brazil). I'll try ur suggestion and let the forum know if I succeed. Wish me luck.