My laptop was setup for wireless ( using pc wireless card ) and RJ45 ( in laptop ) for wire network in company.

While I first time setup wireless at home, it use very well to access internet.
Then I leave my lepatop in company to use wire network and wire access internet for two week.

These few days, I take laptop home and use wireless, but wireless is not work and I can not access into internet.

I try re-setup wireless and re-install pc wireless card few times, wireless still not working.

I don't know what is wrong ?
Someone told me -- maybe your laptop and win xp pro confuse with wire network and wireless network.

How do I can fix this problem ?

Things to check:

If there's an on/off switch for the wireless on your laptop, check and make sure it's turned on.

Open the properties for your network connection and make sure the wireless adapter is enabled. To do so:

Right click on My Network Places icon and select "Properties" from the menu that comes up. In the window that opens up, look at the wireless adapter. Is it connected or disabled? If it's disabled, right click on the wireless adapter and select "enable" from the menu that comes up and try it out and see if the wireless is now working.