Hi Griffin
I would suggest re-installing TS2009, then installing SP2.
If you have created anything, or downloaded anything, this can be backed up by going into Windows Explorer (or 'my computer'), then navigating to the Trainz install directory. In here you will find a folder called 'local'. This folder contains all items that you have created (layouts, paintshed skins, etc) as well as all downloaded items. Make a backup of this folder to another location on your hard drive, then re-install Trainz.
Once you have re-installed Trainz, and applied any appropriate service packs, use Content Manager V2.0 to import the local folder. This may take a long time depending on how much content is in the local folder. Once the import has finished, click on the tab called 'open for edit'. Now press 'ctrl' + 'a' on your keyboard to select all items, then press 'ctrl' + 'm' to commit them. The process of committing the items will take a long time, and it is best to leave it to run overnight.
When you install Trainz, we recommend that you disconnect your internet connection and shut down all programs that are running in the background (including anti-virus and similar).
Now please try installing SP2 again. Before you install the patch, please clear out the Temp folder on your computer. When you are ready to install the patch, disconnect your internet connection and shut down all programs (including anti-virus and similar). Now run the patch. We recommend that you leave the patch to install overnight, and that you do not use the computer whilst the patch is being installed. You may also want to try installing the patch under Safe Mode in Windows.
Once SP2 has completed, use the instructions above to re-install your content.
Please let us know how you go.