Repairing FSX with accell installed ( HELP! )

I have been using flight simulator for years on end. I have decided to upgrade my system to vista 32bit. I have had so many addons all of which have the risks of making fsx stop running efficiently, therefore I backup anything which it asks me to replace. but this time the backups dont even work. (this was understandable as the scenary files were mixed within the rest of the scenary files and fsx was therefore getting confused with which ones to use.
This aside I have been wanting to reinstall fsx so I could clear some of the unwanted files.
I decided to put my fsx delux cd into the drive and click repair. so I did this. installation was fine until I tried to open fsx. where it came up with a registery problem.
So I decided to reinstall SP1 and accel; Registery problem. I also deleted the whole of the fsx directory and reinstalled it from scratch; registery problem when I tried to reinstall accell. I have also tried SP2 but it says accell is already installed and therefore cannot install.
I have tried all possible ways to either get rid or fix fsx and nothing is making sence or it comes up with fsx registery problem.
My fsx is installed on a secondary hard drive and I am running vista 32bit. Is there a way to get rid of everything fsx related on the computer including the registeries so I can start from scratch on installing!??
Thanks
SX~II
This aside I have been wanting to reinstall fsx so I could clear some of the unwanted files.
I decided to put my fsx delux cd into the drive and click repair. so I did this. installation was fine until I tried to open fsx. where it came up with a registery problem.
So I decided to reinstall SP1 and accel; Registery problem. I also deleted the whole of the fsx directory and reinstalled it from scratch; registery problem when I tried to reinstall accell. I have also tried SP2 but it says accell is already installed and therefore cannot install.
I have tried all possible ways to either get rid or fix fsx and nothing is making sence or it comes up with fsx registery problem.
My fsx is installed on a secondary hard drive and I am running vista 32bit. Is there a way to get rid of everything fsx related on the computer including the registeries so I can start from scratch on installing!??
Thanks
SX~II