Internet connected but browser and email not working

Dear Forum:

I hope I'm posting this in the right forum :).

I've been having this problem for a couple of weeks now (Internet connected but browser and email not working) with apparently increasing frequency .

After some 'Startpaging' (i.e. Googling) I found this, which has so far been working but always requires a reboot (I find somewhat annoying 'coz I have to close everything like apps, open browser tabs, etc.):
1) Click on Start
2) In Search box, type cmd then "CMD" will be displayed in the search results
3) Now right-click on "cmd.exe"
4) Select "Run as administrator"
5) Now enter this command: netsh int ip reset resetlog.txt
6) Press "Enter"
7) Reboot your computer.

Now, I'd love to get some feedback with regards to these 3 questions :)
1) What could be the cause of this?
2) Is there perhaps a way to stop this from happening again (short of reinstalling Win7)?
3) If there's no immediate fix to it is it maybe possible to reset the IP without a reboot?

Not sure, if this is in any way related. But also for several weeks now (though I think longer than the IP snafu) the Explorer stops working after each reboot but works just fine (until I shut down my machine several hours later) after it has restarted itself.

Many thanks!

InterMedDude15