Are there other little annoying problems that you put with on the netbook such as the applications not always starting
or email client shuts down for no apparent reason? if so you may have a some malware running or trying to run.
Download, install and run the latest free version of Malwarebytes
I suggest the above because I recently had something called Trojan.LameShield burried away on my main machine, and
only malwarebytes run in safe mode would remove it.
Also do a full scan with your antivirus software.