Computer is slow and freezes whenever it is loading something

Hi,

I have been using my laptop without problems for about 1 year and a half. Recently, about a week ago, it suddently started to be extremely slow and freeze whenever it is loading something.

When I open any website, when I open a picture folder, when I open paint or anything else, my computer just start to load slowly and then completly freeze. The only thing i can move is the mouse and nothing else. I can't open Task Manager and I cant click on anything else. After a couple minutes (depending on the weight of what i am loading i suppose) it will unfreeze and run ok until i click on something else.

Example:
Open streaming site > Freeze > Unfreeze > Click on video > Freeze > Unfreeze > Watch the video without clicking anything > Pause > Freeze > Unfreeze > Play > Freeze..... And so on.

My windows is also very slow to start and close. When my desktop appears, my taskbar theme sometimes changes (won't change multiple times during a single session, only when opening my computer) and i get a windows error (a popup alert, don't remember exactly what it said). Upon closing my computer, there is always explorer.exe running and has to be shutdown.

I have also noticed that my sound is lower then it used to be, even when it is completly maxed out you can barely hear. I'm not sure if it is related but i'm just pointing it out.

Once again, this randomly and suddently happened without any new programs or new websites visited.

I have run AVG antivirus, Malwarebyte antimalware, superantispyware and ccleaner without any improvement.

I need your help guys show me your magic :)
Thanks in advance.

DDS in attachment

bump

Work through these Troubleshooting Steps for Windows 7, immediately establishing a Clean Boot, testing System files and hardware. Report back results as you go as there may be other steps indicated.

I would definitely uninstall AVG which is not recommended by anyone here and install the one in the tutorial, use only those tools and methods which work best for Win7.