To find what your wireless driver is called (i.e. Realtek RTL8187SE) to go Device Manager and look there. Then go to Realtek and in the search box type whatever your model code is (mine was RTL8187SE). On the next page click the link that corresponds to the model code under the Downloads section. From here download the drivers. If there are multiple drivers you choose from it's best to choose the one that works for Windows Vista.
If you have two partitions set-up, one for Vista and one for 7, save what you downloaded in the Documents section (don't unzip it). Boot into 7 and from the Start menu go to Computer and scrounge for your zipped drivers (a little help: Vista (C >> Users >> Ben >> Documents) and now unzip them, if it states it can't unzip them choose the unzip location to just Documents and not the RTL8187SE_Windows_5_6.9067.0710.2008 folder itself. Once unzipped inside the 87SE-PCIE folder launch the Setup file.
IF you get a "Sorry ! Your operating system is not suppoorted !!" error (quite a funny error ) then right-click on the Setup file and click Troubleshoot compatbility. Follow the prompts and choose Vista as the compatibility mode (or whatever your driver works for) and it should very well work.
You're done .
PS: For just the Realtek wireless owners, if its too slow to download from the Realtek website download from here: RealTek RTL8187SE drivers (driverscollection.com may also have other Realtek wireless drivers if yours isn't RTL8187SE specifically)