No it's not a MS site. It belongs to "SlimWare Utilities Inc." the popup you had is an Advert to get you thinking you need to update your Drivers and spend money on their program. Did you notice this part?:
"Download Details: Free Scan for XP, Vista, 7& 8 Price 29.97 1 Year License"
You don't need to update your drivers if you are not having a problem with them.
You do not need to buy a Driver. They are free from manufacturers websites and that is where you should get them from.