Default problem on restore and installing custom rom.

I've restored my MMX a74.. but the user
apps couldn't uninstall.. I've tried more
times in CWM recovery mode too. but
its only wipe the data of all apps... it
couldn't uninstall... and iam going to
install a custom ROM but when I am
going to install it seems only
"installation aborted. I've tried all the
steps and tried to many times but only wasting my MB in downloading....
but I cant.. help me please.....