I am using win vista SP2 32 bit.
I'm sorry, but we don't have any way to test this, because none of us ever uses Vista anymore.
In any case, I strongly suggest you to upgrade to a 64 bit OS, because under a 32 bit OS, the most of memory you can use (in *total*), it's 4GB MINUS the VRAM used by your video card, and this must be shared between the OS and FSX.
This means, even if you have more than 4GB of RAM in your system, the rest will be entirely wasted, and if you have a good video card with 1 or 2 GB, you'll have less than 3GB to use for *both* Windows AND FSX, will surely guarantee crashes and Out of Memory errors even with moderately complex addons.