Microsoft Office 2003 - problems upgrading to 2007

Hi all, my husband brought home a disk with a few programs on it for my daughter who is starting college and needs a word processing program. I believe it has OpenOffice and Office 2007 Enterprise, not familiar with either one. I have MSOffice 2003 installed on my desktop and am happy with it. So I thought I would download this new program on my computer to see what changes have been made etc. but what I didn't realize is that it over-wrote my 2003. I tried opening some photos with MS Pictures and its not there anymore. I also tried opening an excel file and got a message "MSOINTL.DLL is missing... " or something like that and the file wouldn't open. So in frustration I uninstalled MSOffice 2007 and now I see that all of my excel files and word files won't open since now my 2003 Office is gone.
Sorry for rambling here, I tried to do a system restore and picked a date in bold as instructed (just a day ago) and after it appeared to go thru the motions and reboot, I got a message that "unable to restore ..." (don't remember what else). My system restore was NOT turned off so I have no idea why it didn't work.
So I'm pleading now to find out first how to get my Office 2003, is there a place where I can download it? I don't want Office 2007, I want my old one back. My husband has a call in to the IT guy at work who he got the disk from, but as I said, I should have just kept my status quo...you know the old saying, "it ain't broke so don't fix it".
If anyone has any advice I'd really appreciate it. thanks

I'm using XP Home Edition 2002 SP 3

 

I was looking to edit my post but I guess that feature isn't available after a certain amount of time has elapsed? I'm sorry for the original long post, after reviewing it I would have liked to get to the point without all my frustration, maybe even edit the thread title.
Please disregard my post, I uninstalled/reinstalled MS Office 2007 and it must have been a glitch in the original install.