I rooted my new htc one m8.i checked it and YES its rly rooted(root checker app).now i downloaded avast from google play store installed avast and clicked to install anti theft.i selected root installation and then directly written and press further but then i got an error report. u cant write data on the system …? help me pls i want this anti theft tool back 
Hi,
I guess you need to use the recovery method then.
Filip
hi ty for the fast post:).
i tried but then the TWRP recovery said: application failed.i tried again with the direct write method but when i click the button the message appears (…click again) and i click again and then my htc restart directly and when it started a htc error report appears :(.
I will re root and try a custom recovery and then i will test it again maybe the root have some problem but i didnt think so but i will try it.
Okay it works now. :).I uses a app SUNSHINE.apk to get s-off on my phone then i flashed custom rom (Viperrom).Factory reset then i installed Avast and it works with shame 
Btw sorry for my bad english:( iam a little german fag i hope someone can understand what i post there 
Good night guys
wrong section sorry