Hello I'll try to help you the best as I can.
If you are not comfortable with copying Tixati's settings folder manually, you should use the Import/Export function. The error you've got most likely means, that you have tried to save the .tixaticonfig file to a place where you don't have write permission. Try saving the file to the Desktop instead.
In your other topic:
https://forum.tixati.com/support/2451/ you have written that Tixati doesn't find .torrent metadata files. This is because Tixati needs .torrent file only once when adding new torrent to the transfers list. Then it stores metadata in it's own settings files (with .dat extension) within %appdata%\tixati folder.
Of course, when migrating to new system, you have to keep the same paths to downloaded content, in other words you have to copy your tixatidownloads folder to the same place as it was on the old system. Disk letter also has to be the same otherwise Tixati won't find already downloaded files. I assume you have already copied your tixatidownloads folder.
Try following steps:
1. stop all transfers in Tixati
2. go to Settings > Import/Export > Export Configuration To File
3. select all settings
4. save .tixaticonfig file to the Desktop
5. copy .tixaticonfig file to the new system's Desktop
6. install fresh Tixati on the new system
7. start Tixati, go to Settings > Import/Export > Import Configuration From File
8. point to the .tixaticonfig file on the Desktop
9. select all settings
10. Tixati should restart with old configuration and transfers list
This method should work but if you'd like to try copying %appdata%\tixati folder manually, just write I'll try to help. I don't use Windows on my home computer any more. Currently my only operating system is Ubuntu Linux.