Wireless card on MSI s420

Hi all.
Recently I have bought s420 laptop. After some use, I discover one
annoying thing - sometimes my wifi card disconnects from computer (the
Led also changes color).
It happens frequently - maybe twice or more times per day.
I found that if the system is loaded more than average (I use graphic
edition tool) this happens with greater probability, but sometimes it
happens during regular browsing.

Thank you , sincerely Evgeny