Share your experience!
I have Win 8.1 64 bit with Sony PC Companion installed. When I connect my Xperia tipo dual for a system update, it says that I should have Win 7 or below. But later I connected Xperia C and was able to update it successfully. I again tried with tipo, but it doesn't let me do so. Why is this problem with tipo and not with C?
You need to run the program in compatibility mode as far as I'm aware this should fix your issue
It still doesn't help... 
You need to download sony update service and run it in compatibility mode with windows 7.