Running XP-P4-3ghz-2 gig memory-ATI 1650/512 mem & latest drivers.. In the add/remove programs when I click on SP1 or Aceleration it says they cannot be uninstalled. ??? Do I uninstall FSX and will that also uninstall SP1 & Aceleration??I thought I would try a clean install like the latest posts say will give better performance by installing FSX-SP1-Acelleration. all ideas appreciated.ThanksChuck

I just finished that task and sorry I did. I WAS able to click on Aceleration and SP1 and they uninstalled successfully. I also uninstalled some addon's before uninstalling FSX. After FSX was uninstalled and the system restarted, I deleted the main FSX folder. I then tried to reinstall FSX but the screen "Repair or Uninstall" kept coming up which meant I had stuff left in the registry. Ran two registry cleaners and over 4000 registry entries were found leading to FSX. They were safe to delete so I deleted them. Tried reinstalling FSX again and the same "Repair/Uninstall" screen popped up again. This time I went into the registry and manually deleted all references to FSX. I found out later that the FSX folder in my User folder was not removed during the uninstall and I should have deleted those files too. I was finally successful getting the Installation screen to show up and FSX was installed. I skipped installing SP1 and installed Aceleration since it will install SP1 if it's not found. That installation was successful and I immediately spent the next 4 hours running the disk defragmenter. This is critical as FSX throws files all over your hard drive in no semblance of order. I then started up FSX and began receiving errors that such and such scenery could not be found but it started up okay. The error was due to the fact that during the uninstall process, FSX did not remove the old scenery.cfg, FSX.cfg located in the Users hidden folders. I went into the scenery library and deleted those non-existent sceneries.FSX ran no better or worse than before the reinstallation. It was a complete waste of time for me. There was no increase in performance and, in fact, it appears to be running a bit slower now. More tweaking to be done but I'm getting close to having it back to where it was. Defragging your hard drive is extremely important periodically for FSX and will give you the best performance increases.Best regards,Jim