double click you wireless icon.

change advanced settings

wireless networks tab

lists all wireless connections you have connected to.  The bracketed automatic means that it will connect to it automatically.

Manual means you have to manually connect.

if you click on one of them then properties

then connection - there is a tick box - connect when in range

you  can just choose each and remove and then you will have none.

laptops have a key comination or slider switch to turn on and off wi-fi so turn it off if you are unsure,

or  device manager and network cards - disable the wireless card

Install the free version of zonealarm - firewall and only allow needed programs to go to the web.

install the free version of  avira and do a full virus/malware scan

cheers

According to the site: "It could help if you are experiencing any of the following problems:

    * Internet or network problem after removing adware, spyware, virus, worm, Trojan horse, etc.
    * Loss network connection after installing/uninstalling adware, spyware, antispam, vpn, firewall or other networking programs.
    * Unable to access any webpage or can only access some webpages.
    * Pop-up error window with network related problem description.
    * No network connectivity due to registry errors.
    * DNS lookup problem.
    * Fail to renew the network adapter’s IP address or other DHCP errors.
    * Network connectivity issue with limited or no connections message.
    * Windows update does not work
    * You are having problems connecting to secured websites (ex. Banking).
    * Internet Explorer stopped working or crashes all the time.
    * Other networking problems."

Might be worth a look. Good luck.

Forgive me for sounding stupid, but there is always the possibility that you are connecting to another wi-fi around you (such as a neighbor's wifi).

---

 Hey Casey. This issue recently happened to me. I too, only connect to the internet (DSL) when I turn on the power backup/surge protector unit that is plugged into an outlet, & where my router is also plugged into it. I turn it on only when I boot up my laptop, & want to connect. But I could see internet activity on a network meter sidebar widget I have just before I had turned on the power to it. I went to the Control Panel\Network and Sharing Center & it showed that I was connected to my neighbor's wifi that she had not secured. Once I told her, we straightened it out.

So Gibbster, you may want to at least see what's going on in your Network and Sharing Center. Let us know. Good luck.

Like Gioneo said, more details would definitely be needed. 

edit: Wait, is this a laptop? Or a desktop?

Just to be clear, it is impossible for your wi-fi to connect if it is really turned off. Maybe the on/off button is malfunctioning (experienced this b4). Is your laptop also equipped with an air card? If yes, then that might be the one connecting to the net. You can have an air card (usually from your phone provider) alongside a wireless card installed on ur laptop.