Your profile says you are using 1.7.7 do you mean 1.7.7 or 1.7.4?
You can correct your profile by following these instructions:
viewtopic.php?f=16&t=48626If you are trying to install 1.7.4 then please be aware that there were many issues related to this particular version and they were recorded here:
viewtopic.php?f=16&t=44327There are also a few conflicting statements in your post - one is saying port 80/443 are in use where as the other is saying 443 is FREE.
A 404 error means that a file can't be found.
The status check failure (just one of the 1.7.4 issues) can be ignored or rectified by finding a solution in this topic.
viewtopic.php?f=16&t=44320Have you tried to install another version of XAMPP previous to attempting to install this version?
The ports in use usually mean you have not uninstalled the Apache and MySQL Windows services before unstalling XAMPP again if you have tried to uninstall a few times..
You do that by removing the tick in the Svc check box before stopping Apache and MySQL then you Exit the control panel.
These instructions may help if you are uninstalling and reinstalling XAMPP:
viewtopic.php?p=179699#p179699