Office 2003 Installer keeps popping up

Help! About 3 months ago I installed office 2003 pro. Everything went fine then the other day the installer popped up and asked for the cd to install powerpoint, Powerpoint was already installed so I clicked cancel and my powerpoint opened fine. The next time it did it it was for the MS Project. This time I put the cd in and let it do its thing. Then tonight I turn it on and wham as soon as it boots into xp the installer pops up again wanting the cd for project. Mind you at this point I had not clicked on anything. I put in the cd, the little progress bar moved then it was done. That was all! What I want to know is what the devil is going on? When it does this I can click cancel and open whichever program it says it needs to install and it works fine. When installed, everything was set to run from my computer. Any suggestions?