Windows 7 laptop constantly dropping internet connection
Solution 1:
This could likely be due to a power setting. Access your Device Manager and go to the properties for your wireless interface card. In the Advanced tab (or with certain models/drivers there is a "Power Management" tab), there are several power options in this section that may disable your wifi card over time.
I've sometimes deleted the wireless NIC from the device manager to let my computer reinstall it to resolve issues similar to this.
Solution 2:
Long shot... but I've had similar experiences which I resolved by locking my router to a particular channel.
Most routers nowadays are set to hunt out a quiet(er) channel if they experience heavy traffic (collisions?). Additionally, many are set to prefer to use channels 1, 6 or 11 (802.11bgn 2GHz). I found that using channel 3 is best for my area, with another option being ch 9.
Try locking your router to a single channel, turning off the 'select best channel...' options.
Seems that the router is jumping channels to find a less noisy frequency, and Windows then has to go hunting for it, taking time, 'dropping' the connection in the mean time.
If you're an Android user, the "Wifi Analyzer" app by Farproc is very useful to show channel usage in your area.
Wifi Analyzer by Farproc (Google Play)