Steve's Dell Inspiron laptop drops Wi-Fi all the time. Dell claims to have fixed it via remote access, but it didn't work. Leo says that it's likely the person at Dell tech support had very little training and was following the directions in the notebook. All too often it doesn't fix the problem. What he'll need to do is call them back and ask to have his case escalated to tier 2 or even tier 3 level support.
Why does Wi-Fi drop out? It could be congestion. The 2.4ghz band is woefully crowded. Also, Wi-Fi Networks could be dropping out while other networks are in heavy use. More likely, the problem is his router. Routers provided by ISPs are usually very basic modem-router combos. It's probably older, too. Leo says to turn off the router portion of it and buy his own. They are newer, more secure, and updatable. Modern routers are also dual band, which are at 2.4 and 5.0 ghz.