i cant deauthorize all my computers.its showing that u can do it once a year and telling to wait until 24 december 2014.Recently i want all my apps back and i cant authorize my recent computer so please help me to deauthorize all my computers.

Have you really authorized and then lost access to 5 computers since 24th December (the last time you de-authorized all computers?) If you still have access to them, just de-authorize from iTunes: the Store menu, then Deauthorize.

Matt

Since it is giving you a specific date, did you deauthorize one or all in December of last year?

The only way I know of (until December) would be to contact iTunes support and ask if they can make an exception and deauthorize them for you.

http://www.apple.com/support/itunes/contact/

That is strange then - did anything else happen with your account at that time?

I'd suggest contacting support then - they may be the only ones who can figure out the problem.