Why is my laptop backspacing/deleting content and webpages?

I have an Acer Aspire 5810T with Vista installed. For the last 3 weeks I have experienced several problems which I have been unable to fix. These are: - backspacing content in google docs and word/office programs. Cursor just suddenly begins backspacing at random intervals. The mouse used to freeze before this happened although the mouse no longer seems to freeze. - Webpages click back to previous pages or to brower home page. Happens in both chrome and firefox - Opening windows such as control panel results in rapid flicking between desktop and CP. - Laptop no longer automatically boots to windows - I have to hit enter. This problem developed a week or so ago. - Intermittent 'pinging' which can last several minutes I have run a virus checker (Mcafee is always running); run a malware program, updated drivers, used system restore to a point before this started. Nothing has worked. I think this maybe an issue with the touchpad which I uninstalled or so I thought yesterday and was using an external mouse. Issues still continued and the touchpad is still working despite it no longer appearing in the device list. Any advice would be much appreciated!