FSX re-install . Do I need and How?

Hello fellow Simmers,Yesterday I suffered from an un-explained crash of my PC after updating my Nvidia drivers. It appears that the BIOS was damaged and in order to recover I had to re-install it (I actually installed a new version). I know that's not an H/W forum but here is why I post it here:After the BIOS re-installation everything seems OK and I happily lanced FSX and thought that everything is back to normal. However, since then I incessantly receive windows error massages, I cannot open FEX and ASA and every applications (like Nhancer) I try to install it crash during the installation! So I came into the conclusion that perhaps my registry was distorted and I don