Microsoft Office installation is very simple, pretty much just a series of clicking ‘Okay’ or ‘Next’ at each dialog during the Microsoft Office installation process.
If you do not complete the registration you will only be able to perform limited use of this software.
When finishing the Microsoft Office installation the option to delete the install files comes up in a dialog box I suggest not deleting. You need those if you have to make a repair to the software, at any time for any reason, so keep them.
Microsoft Office installation starts automatically after you have inserted the installation media and runs pretty much on it’s own but there are several things you can do to modify the way Microsoft Office installs on your system.

If you are running anything other than Windows XP Pro SP3 then scroll down to the Windows Vista or Windows 7 sections.
If you are still running Windows XP the first thing I would suggest is that you upgrade your OS. Running Windows XP is comparable to being an over 60 baby-boomer with a ponytail. If you don’t get that then I don’t know what to say. But I digress. My point is you cannot even buy Windows XP any longer so that is a indication that it is time to upgrade. If you are not able to upgrade for any reason then read on.

So let us assume that you have some version of Microsoft Office installed on the computer and you are having a few problems with the way it is functioning. The application had been working properly and for some reason it has stopped working. If you left the install files on your system during the original install then open up the control panel and select ‘programs and features’ or ‘add remove programs’ depending on which OS you have.

Scroll down to the Office installation and highlight it. You should see a ‘change’ button. Click on it now.
Once you have selected the ‘Change’ button the Microsoft Office installation dialog will pop open and you will be prompted to select from ‘Repair’, ‘Add features’ or ‘Uninstall’. In this case you would select ‘repair’. This is the reason to not delete the install files when you are installing Microsoft Office on your system. After the repair utility has completed most of the issues you had will probably be fixed.