Trouble with getting Microsoft Office to work

[Simrad]

Hello,
I have the 2003 version of Microsoft Office and recently downloaded the
trial version of Microsoft office 2007. I have then deleted the Microsoft
office 2007 trial version off my computer and I now cannot access any
Microsoft office software on my computer, so I am unable to open or create
any word documents. An error comes up on the computer and says that I need to
install the cd rom of microsoft office but i am unable to find the cd rom.
What can i do to get my microsoft office 2003 back???

Thank you