|"The issue that started all of this was not being able to open attachments in Outlook.."|
You can look up how to do that on the web, for the particular file types you can't open.
"....so first I tried changing the registery keys to allow those files to be opened, ..."
If you're going to mess with the Registry, you should make a backup of the existing Registry so that you can load that if you need to later if mistakes are made, without having to load a previous restore point.
"....and then realized that my exel wasn't on my computer anymore. I tried to reinstall Office 2003,....
If the Excel version you're taking of was the one included in Office 2003, you could have chosen to do a Custom or similar installation, rather than the default Express or similar installation of all of Office 2003, and installed only Excel.
In any case, Microsoft has free Readers in it's Office support for Excel, Word, PowerPoint, etc. that you can install that can open, but not edit, their file types.
OR - you can load the freeware open source Open Office and open and edit any Microsoft Office file type.
"....which updated my outlook and I lost all my emails! "
You are supposed to follow a procedure to back up any existing personal Outlook emails and associated personal data - contact info, address book, etc. The result is all in one file. After you have loaded Office again, you can restore your previous personal stuff in Outlook with that file.The info about that is in Outlook's Help,and on the web in many places.
That data is deleted from C:\Documents and Settings\your user\somewhere in your user files and folders and does not appear in the Recycle Bin. It's stored in the same place(s) as your fresh Outlook installation stores it's files.
The data is still there initially but has been flagged in the NTFS MFT (Master File Table), or FAT32 partition table, with a character that indicates to Windows that the space the data occupied is available to be used for other data.
If you want to have the best chance of recovering that data intact, the sooner you use some sort of un-delete program to recover it, the better, because the Windows page file (swap file) will eventually overwrite the location of where the data was located.
For that matter, the very best way is to stop using Windows when you realize the data is gone and connect the drive to another computer with an operating system on it so that you're not booting the other computer from your drive and run the un-delete program on your drive.
E.g. links to some programs that can un-delete data are here -
see response 2:
Personally I don't use System Restore to load a previous restore point until I have tried everything I can to fix the problem, whether that's something I already know or something I found when I search on the web.
I'm a lot more likely to try doing a Repair installation of XP rather than loading a previous restore point if I can't figure out how to fix a problem - it takes less than an hour to find out whether that solves the problem.
I avoid re-installing Windows from scratch except as the very last resort - you don't learn how to solve problems by doing that.