Hi Sanal.

I have a suggestion, but it requires quite a lot of HDD space. If you have enough HDD space to do so, give this a try:

Restart your computer and DO NOT try starting FSX after the restart (it might not allow you to the next step!). After the restart, rename you FSX folder. For me, I renamed F:\Flight Simulator X to F:\FSX Backup.
I strongly recommend that you delete the fsx.cfg file, but you don't have to if you don't want to.
Place the FSX DVD int the DVD Drive and select the Repair option when given the choice to Uninstall or Repair. The FSX DVD still thinks that FSX is installed in F:/Flight Simulator X and so it will do a complete reinstall of itself there. Reinstall SP1 and SP2/Acceleration.

I do not delete my Logbook.bin file. The one I am using now is from 2009 and has been through several clean installations of both Windows XP and Windows 7. I have had to repair it quite a few times (I can send you the program if you like), in which I might lose a few logged flights, but it's better than losing ALL of them.

Reinstalling your FSX add-ons is different and will depend on the add-on itself, some (like Captain Sim) can be "repaired", even though they are not where the installer believes them to be. Others will need to be uninstalled and reinstalled. An uninstall should not touch the aircraft in the original FSX location (which was renamed) so it doesn't know they are there. Windows might tell you of a missing uninstall log (or something like that) and so can't uninstall it, but it might ask if you want to remove it from Control panel Programs and Features (Add and Remove Programs in WinXP). I usually say yes, and then reinstall the add-on. It has worked for all I have done so far.

Once all that is done. Any modified aircraft.cfg and panel.cfg and pretty much any other changes you have made to your add-ons can be carried over from the renamed FSX folder into the new FSX folder.

I'm still in the process of bringing things back to my new FSX installation after I did all the above about a month ago.

Hope his helps

Mark