SP1 - Installation without Loosing Current Files

I've been asking here and in other forums whether Microsoft's update FSX_SP1 really requires starting with a clean (freshly installed copy of FSX without add-ons or usage history). Here's one way I've found, experimentally, to do the update while preserving Settings, Saved Flights, Rewards, Add-Ons, etc. It's really not so hard.

A. Backup your computer or insert a Restore Point.

1. Remove all manually installed add-ons and park them in folders where you'll be able to easily re-access them.

2. Trash add-on scenery installed by commercial vendors, e.g. a MegaScenery folder wherever you installed it.

3. In the Control Panel, use Add or Remove Programs to remove FSX - BUT, when the dialog "Remove" or "Repair" appears, choose Repair. Then insert the two original FSX disks when prompted.

4. Run the Microsoft update, fsx_sp1_ENU.
NOTE: I found that some of the scenery items deleted still appear in the Scenery Library if FSX is restarted at this point. To be safe, I simply deleted them within FSX before proceeding to Step 5.

5. Reinstall your previous, manually installed add-ons and re-run your commercial installers. (If you have FS2002/2004 files from MegaScenery or Megacity, then run their converter, e.g. FS2004FSXLibraryUpdate, to make them compatible with FSX.) If, in the process of reinstalling your commercially acquired files, or any other files added with an installer (vs. manually), other scenery in the Scenery Library disappears, those files aren't overwritten. Just use Add Area in the Library to reinsert them, assigning them the priority (in the Library) that you prefer.

This seems to me to be a safe, straightforward way to install FSX_SP1 without loosing anything. There are probably easier ways, but I haven't found them posted here or elsewhere, including at Microsoft.com.

Martin