B1900D Install After 737NG Hosed Something

If this has been addressed before, my apologies. Just point me to the thread for the answer.I've had the 737NG (all series) for some time now and they are great. Yesterday I purchased the B1900D and ran the install routine for it. It seems to have completely over-written the PMDG folder in my FS9 directory. I no longer had any of the 737NG folders under the PMDG directory. Only the B1900D Express, PMDG Express, and an ICON folder. All my flightplans (and the folder) disappeared, the SIDSTARS folder was gone, and the main PMDG folder is missing a bunch of INI files from before. I manually created a new 737NG folder and can re-add the manuals that were there. I also manually created a SIDSTARS folder and updated it with the current 0410 SID/STAR download. Same with the Flightplans folder, but I'll have to re-create all those for the 737NG it looks like. I ran FS9 and all the 737's are still there and they seem to work OK (I can pull up the FMC and get the 0410 Navdata and the SIDs/STARs) but when I exited FS9 the only INI file that now shows in the main PMDG folder is the "737guages.ini" one. A friend of mine says he has several other INI files (737Airlines, 737Kbd, ACS, LoadManager) and also the LoadManager.exe file (which I can't find anywhere right now), along with a couple other ReadMe files I no longer have there.I have no idea what happened when I installed the B1900D. Anybody got any ideas, or how I might be able to fix it, short of a complete re-install of the 737NG?Thanks for any advice.FalconAF