|Might be as ijack suggests...|
But it wouldn't hurt to run a few cleaners - if only to check for a few possible pests running in the background?
Run these in this order;and keep any logs generated for further consultation/examination.
Junkware Removal Tool (JRT)
JRT installs to the desktop - from where you run it. It will open into small dos style window; follow the instructions therein. It will reboot the system as part of its process.
All of the above are "free" and safe to use; and regularly recommended here.
Instal each of the above using the "manual/custom" option; do NOT use the default/automatic option. Carefully watch for and uncheck any (so helpfully pre-checked) boxes - other then the one for the utility itself. This way you will avoid installing all manner of stuff which you neither need nor want. Some it isa real PAI to eradicate...; much of it runs in the background, and/or makes changes to the system - without you being aware.
Post back with the results afterwards?