MS Word 2002 does not display type

What would cause my MS Word 2002 program to stop displaying the text that I enter on my keyboard. I am running MS Office on a Pentium II 233 MHz machine with 64 MB of RAM that is using WIN98 as the OS. The OS is installed on C: with 1 GB of space. All my apps are installed on D: with 2 GB of space. When I use other programs that require text to be keyed into them I have no problem.