First, turn off antivirus protection, and maybe the firewall. I didn't do the firewall. Find the UserData folder, copy and paste somewhere else. This will be a backup of what you have. Then, you can go ahead with the patch #2. If it fails, all you need to do is reinstall TS12, apply SP1 and patch #1 , then delete contents from UserData folder, use your backup data, copy and paste it back in. You will be right back where you were. Suggestion: Click a check mark in the box for the developer option called, "show database process windows", so you know when the system is not busy, and also, whenever you close trainz, wait for those developer windows to disappear before you shutdown or reboot. You will have less database management problems.
Paul