I do not have a wallet but i will try guess it.
Start-Search-CMD- = Should open a Command window.
Right click whitecoin wallet and look at the location.
Type the location into the CMD window.
example
You should see somthing like this = C:\user\name>
You need to type desktop\NameofWCapp.exe -rescan
I think this is correct. The wallet should load and say rescanning. leave it alone! sometimes it looks like it has crashed. just leave it.
If that doesn't work, try the same thing but with -reindex too, for example
You need to type desktop\NameofWCapp.exe -reindex -rescan