Hi there and welcome
There is no update, apart from upgrading windows vista to a later version, but note, Chrome and Internet Explorer will continue to work, it is just you do not receive any added functionality or updates but it will continue to function as it is now.
If your only concerned about the browsers being upgraded then you can continue using the computer as it is. you wont gain any additional functionality, but you will not lose any either.
If you would like any additional information or assistance, please do not hesitate to let me know.
Else if you can take a second to rate my service by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.