Xp Freeze

Hi, i need your help. I really have a big problem with my pc.
I have XP Home SP3 and Avast free version SINCE 2015. A PC Week keeps my frozen for long to Other and I even trouble to start it.

Is anybody has the same problems?

What exact version of avast ?
Any other security (related) software installed ? (or was there)
What do the windows log files say ?
When did it start ? (e.g. after a update or something)
Already removed all dust from inside the pc ?
Ran hardware tests ?

I have Avast free version 10.4.22.33 2015 . I use Firefox as browser on XP Home sp3 .

And my problem started Monday, February 8, 2016 .

You could start with installing the latest version, and make sure all previous AV’s have been uninstalled and cleaned up with their individual removal tools.

Remember to choose custom install to remove any unwanted features.

https://forum.avast.com/index.php?topic=182468.0

What happened on 2/8 ??? What was installed or changed on that date ???