I have a Toshiba with Windows 7 and I was able to connect to my internet wireless-ly and then I went through my computer deleting many things and now i can't connect to my router without an ethernet cable.
Can you connect to the router wirelessly with another wireless device? Can you verify that the router's wireless is ON? (Check the web interface.)
When you go to adapter settings (Start->Control Panel->Network and Internet->Network and Sharing Center->Change adapter settings (from the text menu on the left), can you identify your wireless adapter, alongside with the wired one? If you can see it, you can right click, and disable, then enable it again, see if this changes anything.
I think it's a driver issue, you said you were "deleting" stuff, I beleive you mean "uninstalling", go to your manufacturer's webpage and search for the driver.
Please include the model number and etc. for your Toshiba, go to Computer>System Information. You will find everything there.