how can i stop my dad viewing my history?

basically my dad is very nosy lol, he always spies on me and my mums internet history and im fed up of it. i've changed my browser for internet explorer to safari so he cant look at the inex.dat files. i also use c cleaner is there any other way he could look at my history?
Thank you

CCleaner is good tool. I have no experience with Safari, but I recommend Mozilla Firefox where you can safely delete your browsing history, cache, cookies, passwords and other stuff by Ctrl+Shift+Del (or Tools > Remove personal data). You can actually choose, which you want to delete... if only history and cache... you can, and you can keep other files in computer. In CCleaner you can set Firefox to be cleaned as well.

Quit giving him reasons to mistrust you.

spying on your mom too,... wow, that's very much nosy... delete all the history possible...there is something called keystroke logger, this can be put either as an hardware which is visible to the naked eye. it will look something like an usb stick. or it can also be put as a software. but, you can detect it if you have an antivirus, because, for the antivirus this software will be like an virus. so try either of these.. and tell your dad to stay out of your private matters. you are above 18 rite???

Stop viewing porn on his computer...*L*

go to my computer press cntrl+h and delete wat all u need ...
if u r using internet explorer ,
rightclick ----> properties click on clearhistory ....
start ->run type RECENT and click OK and delete all the files in that folder ...
no one can trace u ...
enjoy ....... :-)