my download viewer or download manager has gone wacked.

when I download a program or try to update any program it repeats the download . it will save as only, it will not run and save, will not download the program. it piles up pages and repeats the download. ??help please i can not do a thing.. 9iF THERE IS A WAY i CAN TURN IT OFF , i CAN NOT UNINSTALL NO PROGRAMS OR INSTALL. . NOT EVEN AN ANTIVIRUS PROGRAM, I HAVE PRO MALWAREBYTES ANTI MALWARE . I CAN NOT TURN ON A REGISTRY PROGRAM , NOTHING,

thank you !

kev