Fsx Key Free Flight Simulator X Question?

Flight Simulator X question? - fsx key free

I have FSX Deluxe Edition. It has two panes. I bought a while ago and now the attempt to install on a new computer. The problem is that I lost the second disc. Is it possible to replace the lost hard drive? Microsoft does me a free, new? I still have the product key

PLEASE REPLY IF YOU KNOW !!!!!