Not abe to update latest version of wordpress

I have tried to update to the 3.5 version of WordPress 3 times.

I did what it said to do I entered the appropriate info that it asked for. I clicked “Proceed. It said it was unpacking the files and then it said it was installing the files,etc., it then went into “maintenance” mode for about 10-15 minutes then it went back to my Dashboard and said the update had failed. to try again. I did try 2 more times each time it said the same thing. Note Prior to my attempt to update, it did say that my plugins had all been installed successfully, and that I successfully installed an updated theme and an updated version of akismet. In the note section of my Akismet it says you are using 3.5 version of wordpress. That does confuse me. As it says at the top of the page that it was not successful. Is there a way to tell if it did update, and the error is at the top of the page saying that it did not. Thank you for your help