DLL!

I uniinstalled FS9 recently and now cannot re install the programme.
Following installation when I try to open FS9 I get the message Could not load dll! Flight Simulator will now ext.. I re installed a new version of XP and tried FS9 again with the same result.
Is this a computer problem or an FS9 problem.
Thanks in advance.
Following installation when I try to open FS9 I get the message Could not load dll! Flight Simulator will now ext.. I re installed a new version of XP and tried FS9 again with the same result.
Is this a computer problem or an FS9 problem.
Thanks in advance.