Hi,
Welcome to Microsoft Answers community.
With which application are you having this issue?
Do you use both the languages at the same time?
If you can see the keyboard icon on the status bar, right click it.
1).Click Settings.
2). In properties window,
3). Click Advanced key settings.
4). Click the Change key sequence button.
5). Select both not assigned buttons there.
If you are facing this issue in Word you might have to try the steps mentioned below.
1). On the Tools menu, click Options, and then click the Edit tab.
2). Uncheck the Auto-Keyboard switching check box.
I would also recommend you to post your query in Office forums if the issue is with office applications.
http://www.microsoft.com/office/community/en-us/FlyoutOverview.mspx
Let us know if this helps
Regards
Sreekanth.