How to delete PCWebStat.com pop-up hijacker on browsers completely?

I use Google Chrome & Avast internet security. I have a Dell, Windows 7 laptop that is just over a year old. The avast has been working quite well. However, over the past couple of days my internet browsing has been interrupted quite frequently by numerous types of pop up ads, usually it gives me PCWebStat.com pop-up. It is really annoying. I run Avast scan but it shows nothing. Any help to remove this pop-up will be highly appreciated.

PCWebStat.com Hijacker – How to Remove?

PCWebStat.com pop up is a misleading message associated with browser hijacker or adware which is able to pop up in all your web browsers including IE, Firefox and Chrome without your permission. As soon as it is arrived, it modifies the browser default settings and then causes you constant troubles when searching online.  For example:

Home page is replaced and favorite search engines are disabled.
Unknown toolbars or extensions are automatically installed.
Browsers are blocked constantly by similar pop up police alerts.
Regular websites may not be accessed as usual due to the complete block of this scam page.
…

If you get PCWebStat.com pop up ads frequently on your browser, then your computer must be under attack. Although it seems to be a convincing web page asking you to download the latest flash player. However, there is no reason for you to click on the pop-up and continue the installation because this is a fake message. If you follow what it suggests, your computer will be more vulnerable for further attacks. What you download from this page may turn out to be a virus or spyware that poses a risk for your computer security. Besides, this adware replaces your homepage and search provider secretly and interrupts your browsing activity every time you open your browser, you have to delete it without any delay in order to safe your computer.

How to delete PCWebStat.com pop-up hijacker on browsers completely?
Can I run security scans to get rid of the adware? Will system restore work? I also uninstalled the programs from the past couple days but the problem remains. To completely get rid of the adware program and stop these pop ups, a manual removal is introduced in this passage as an efficient way that guarantees a complete restore of the affected browser. Other than resetting browser defaults, you will also need to get rid of unknown extensions on browsers and check for potential malware. Expertise will be required during the manual process to complete the clean.