If your internet browser has slowed down, or you are seeing more adverts or pop-ups, it is possible that you have picked up some adware.
Adware is often installed as an add-on into your web browser in the same way as a legitimate extension. Once installed however, these malicious programs can sometimes be hard to remove. Common examples include Genieo, and Spigot.
There are many ways of removing this, including Apples own instructions which can be found here. The apple instructions require some technical knowledge.
A much easier alternative, which I can recommend is Adware Medic. This is a free tool that will scan your system and remove anything it finds. If you find the tool useful, you can donate on the page.
If you still need help, you can call our shop on (03) 4282911 and arrange for a repair.
Always make sure your computer backup is up to date before deleting system files.