When deleting a programme I accidentally deleted my wireless device, and would like to know how to reinstall this.

Please provide few more information related to the wireless device:

1) How did you delete the wireless device?
2) Are you referring to software for wireless device under Programs and features?
3) What is the Make and Model of the computer?

Well, you can refer to the link to add a wireless device on the computer:

http://windows.microsoft.com/en-IN/windows-8/add-device-or-pc-to-network

If you are referring to the driver for the wireless device, you can refer to the manufacturer website to download and install driver. You can also find the utility software from the website related to the wireless device. Refer to the link:

http://windows.microsoft.com/en-in/windows/network-connection-problem-help#network-problems=windows-8&v1h=win8tab1&v2h=win7tab1&v3h=winvistatab1&v4h=winxptab1

Refer to the link for further reference:
http://windows.microsoft.com/en-in/windows/set-up-wireless-router#set-up-wireless-router=windows-8