Lately, I noticed some unwanted commercial advertisements popping-up on this site.
How does one get rid of them?

Sounds like spyware/adware... I do not get any advertisements. I would download the following; malwarebytes free and superantispyware. Install both and run them. They should dig up and find something if you feel something is not right with the computer.

I don't get any either.  You probably surfed the net and nullzero is right.  Get rid of that malware or spyware. 

Suzi

Just to get started, if you're browsing the internet with something that isn't Google Chrome you're not caught up to 2013!  (and if you're using internet explorer, you're not caught up to 2004!)

All of the serious browsers (Firefox, Chrome, Safari) have adblock addons that you can toggle with a click of a button.  Chrome also gives the option to sort who can advertise to you if you want to see *some* popups.  

Mac for the win!

But yes, taunting aside, it is probably malware. Greg above listed some good, safe options for web browsing for PC users.

Nichole,

Macs are not immune to problems, they are better then most PC users though. Lately I have been experiencing lots of Mac problems with build quality etc., Safari also crashing and causing issues. Its been a growing theme with peoples computers that I fix, I think the build quality has gone down lately (personal opinion and experience). Remember when more users switch the mac viruses and malware will follow.

The best preventative measure, is safe browsing and email habits. Don't open anything in the email unless its a trusted contact and you were expecting a specific file or picture from them. Also obviously going to xxx sites and other stuff, will lead down a road full of viruses and other malware. Having a good anti virus software is a must. I recommend the Pro version of Malwarebytes, this is the most robust and easy to use virus scanner (it has no BS and does not bog down the computer like others). However, I also recommend having a second anti virus/anti spyware program like spybot search and destory/superantispyware/avast.

No site advertisements on this old machine luckily useing freeware called Adblock .

George like others said you probably have some sort of spyware/adware on your computer .
I hear some app's also can install them in backround - not sure.
But im no computer wiz by far.

http://www.ubuntu.com/ubuntu/why-use-ubuntu

i had few of those couple of days ago. i started going over any software that i didn't install and removed them. since then, no issue. 

Hey Gorgi, go download a free copy of Malware Bytes and install it:  http://software-files-a.cnet.com/s/software/12/89/74/68/mbam-setup-1.70.0.1100.exe
Run a full scan on your computer.  If you have malware on your computer causing this, I would almost guarantee that MWB will find it.

On the MacOS vs. Windows vs. Linux (and or Mac vs PC) argument... I work in systems security as a profession, and I'll be the first to tell you that Mac is just as vulnerable these days, but the infections on Mac are wicked sick and often go undetected because the users don't know what to look for and think they're immune to attack.  Unfortunately, now that major corporations like Google require their staffers to use Mac, the hacking world is making more of an effort to target them. 

If you want to see examples of self-installing, no-password-required nastiness that has been targeting Mac the last 12-18 months look up:

* OSX/Crisis
* Wirenet.1 Backdoor
* Flashback Trojan

Something else you need to watch out for is bundled Trojans.  The Bad Guys are injecting malicious software into legitimate installers as well - one example from end of 2012 targeted users of VKMusic4 - malicious software was bundled into the installer for that legitimate software title and infected a lot of places, ran up a lot of monetary losses for folks.

So... Hate to break the news to y'all Mac users but ... you aren't much safer.  If anything, you're worse off, because you don't know what to watch out for, and this stuff installs without your consent or knowledge.  Windows users might even have a leg up now because they have ample titles at this point to keep you clean.  While it's novel that Apple is using blacklisting to prevent the latest rounds of zero-day Java DBM attacks you'd encounter while surfing the web... that only goes so far.

Just sayin'.

Thanks all for all your answers.
Looks like my PC needs a good cleansing bath!

I second the Adblock Plus suggestion. Even with no spyware you will see advertisements on a lot of websites. With Adblock they are not there. No ads, pop up or otherwise, ever.

http://adblockplus.org/en/firefox

For most people on a PC a combination of Google Chrome (free) 

https://www.google.com/intl/en/chrome/browser/

and AVG antivirus (free)

http://free.avg.com/us-en/homepage.tpl-stdfull

will let you surf the web pretty much worry free from virus/malware problems.  Or if you have a mac Safari 6 or better w/ mac adblock (free)

http://safariadblock.com/

I don't mean to be contrary Greg, but I'd advise against that free AVG.  It is a resource hog (chews up lots of CPU and bandwidth on your computer), and it's not nearly as effective as Norton or McAfee.  But you raise a very good point:  combine an antivirus AND an anti malware / adware program.  Not just one or the other.  From my experience (my own machines and those that I've supported for colleagues), I second the opinion for Malware Bytes as an anti malware package (it's free, good, and doesn't eat up lots of cycles from your computer), though I think there are lots of good choices for anti malware.  But there's very big variation in the quality of the anti virus packages, and AVG has gone down hill (in my opinion).

Mike   central NY state, zone 5  

Not trying to call you out, Greg, but Chrome is just as hackable as is Safari as is Firefox as is Internet Explorer, really.  Thinking to the contrary is outdated by 5-10 years.  Chrome was proven to be insecure once again a few months back when Google did their routine offering of large sums to find anyone that could hack it with very specific guidelines, and it was hacked the first day.  More info on that:  http://www.nbcnews.com/technology/technolog/google-gives-man-60k-hacking-chrome-368666 - and it's not the first time that this has happened, several people have proven that Chrome is extremely exploitable a number of times in the past. 

Don't fall into the Mac-user mentality of "I'm safe because what I use isn't hackable".  It's just not the case.

This is the reality:  It doesn't matter much what browser you use, your surfing/usage patterns are more important than what you use and/or use to surf.  Your major, glaring vulnerability isn't so much your choice of web browser, it's the add-ons you have installed on the browser - Java, Acrobat Reader, and Flash being the big three which are responsible for the vast majority of drive-by infections, the most exploitable elements of your surfing experience.  Just disabling the add-ons in your browser drastically decreases your risk of being infected with the 10-ton elephant in the room (drive-by malware).

Firefox has the greatest potential to be most secure if you're using the NOSCRIPT add-on with it, which will kill the vast majority of XSS/drive-by scripting routines that attempt to exploit the aforementioned plugins.  There are a couple of plugins for Chrome that act similarly, but aren't as effective.  And just using NOSCRIPT isn't good enough - you need to be smart about how you use it, understand how it works, etc.

Knowledge is your friend in the new millennium.

My experience has been that AVG is just as good if not better than Norton and McAfee.  It gets upgrades faster for one, free is good too.  Norton and McAfee are good too.  I'll tell you though I worked in internet tech support for a few years and handled hundreds of virus calls a month.  Any time I took over a customer's computer remotely to help them I would go straight for AGV free and it solved the problem every time *if* it was genuinely a virus/malware issue.  Coincidentally a lot of calls about virus problems were actually anti-virus software issues...  

Anyway, I'm not saying AVG is better necessarily than pay-for antivirus software; just that it is at least pretty close, at best better, and it's free! :-)

As far as Chrome, I think any browser is hackable, but I'm not sure people really get their browsers hacked.  If you're getting hacked your browser is irrelevant.  For me browsers are all about functionality.  Chrome's biggest drawback is that it eats so many resources since it opens each window as an independent .exe for instance, but that feature also means that if one tab crashes the others are fine.  Having the address bar double as a Google search box is convenient for me, I like the built in spellchecker a lot.  Youtube options, interaction with Win 7/8, and just minor stuff like that.  All of the minor stuff FireFox and Safari can easily do with addons though.  

Really what I'm trying to say is don't use internet explorer lol.

Thanks for posting this and for all of the responses!!!

I've been having issues too - no ads -  system resources down to 10% !!!  I almost use this computer the way I have always used it.  I don't download music or videos (don't know how too!)  I don't even know what to do with MP3 and anything media unless it comes from my camera and I upload onto the computer and then to here or photobucket.  I have run the scans using Norton, Spybot, superantispyware, and  malewarbytesfree from post #2 by nullzero.   A bunch of cookies were found and deleted, so I'll see what happens over the next few days.

Why can't these things run like my mixer??? On/Off low med high speeds ;)   Some things are just so much easier too operate - even my car LOL LOL LOL

Ad awear goto http://www.cnet.com ant type that in the search box. Saved my pc and is free. Lavasoft

I run Linux and it works for me. :)

A huge mistake is using Norton and McAfee products.  You're better going with Avira, Avast or AVG.

Greg, the vast majority of system infections start with a user browsing the web using any browser these days, regardless of who makes it.  Again, entry point to infect is typically browser plug-ins that are present on all systems, regardless of OS:  Acrobat, Java, Flash.  If you want to research a typical variant of one of these types of malware, go read up on "Pidief", which is often used to exploit the Acrobat/PDF plugin of any browser.  The three plug-ins I just listed exist in nearly any browser on a Windows system, often are also found in MacOS, even found in your major favorite Linux distros like Ubuntu, Debian, FC, etc. 

Browser hackability is important because it expands what an anonymous website is able to do to your system after, for example, exploiting one of the aforementioned plugins.

This isn't to say that we don't see typical attacks these days by email, etc...  They still happen.  I discovered a new variant of Kryptik today in a crafty email targeting myself and a coworker, it originated from a major metro area of South America. 

The internet is a dangerous place these days... especially if you don't know intimately what's out there and how things work behind the scenes.....