I read someplace that it is good to delete all of these files after you install scenery and let fs rebuild it all to prevent ctd's is there any truth to this?

Hi,Nope, don't know where you read that!Jimhttp://www.hifisim.com/Active Sky V6 Development Team Active Sky V6 Proud SupporterHiFi Beta TeamRadar Contact Supporter: http://www.jdtllc.com/AirSource Member: http://www.air-source.us/FSEconomy Member:http://www.fseconomy.com/

hmm, alright, what do they do then anyway?

Hi,Do you mean your scenery.cfg file or scenery.dat files? I just searched and did not find one scenery.dat file on my whole system!Jimhttp://www.hifisim.com/Active Sky V6 Development Team Active Sky V6 Proud SupporterHiFi Beta TeamRadar Contact Supporter: http://www.jdtllc.com/AirSource Member: http://www.air-source.us/FSEconomy Member:http://www.fseconomy.com/

Yes scenery.dat, you should have quite a few in your fs folders. If you search your root fs9 folder you should find a lot,I usually get around 60.

I think scenery.dat files will be put there by various addons, and have no part or influence in the scenery.cfg - which is the library file rebuilt by the FS upon restart.

They are just data files that aid in speeding up the "memory" or loading of what's been added or used. Each add on scenery has one (scenery.dat). You can delete them and FS9 will rebuild it at the next start up. If all your sceneries are onboard the FS9 platform then the scenery.dat file(s) will be in that respective folder (such as in ...Flight Simulator 9Addon Scenery). Same goes for sceneries kept off the FS9 platform. There is also a SceneryStatus.DAT in the main FS9 root folder. It can be deleted as well and will be rebuilt at a fresh start. (note: do not delete the scenery.cfg, it will not be rebuilt)A time change in FS9 forces a data (.dat) rebuild as does season changes.Your computer is full of .dat files that "speed up" trips to frequently visited web sites, emails (outlook and outlook express), and loads of software programs. Each is program specific, so requires that program to open them up and/or read the data. A google search will even produce a couple of utilities that claim to be .dat readers.

Yes, there is truth to that. Although it's not necessary to delete all of them if you add one scenery. But as you make changes over time, it's a good idea to to delete them once in a while and let FS build fresh copies. I'm not sure who told me this, but apparently it's good for FS and in some cases it may very well cure crashes that can't be explained.