Take your computer to safe mode with networking and use the below link to re-enable the task manager :
http://www.howtogeek.com/howto/windows-vista/why-is-task-manager-disabled/
After enabling the task manager please make sure to deactivate the antivirus completely from your computer. Run a scan using any of the tools: Trojan remover & roguefix (check with website: www.filehippo.com)
After the infections has been removed reboot the computer to normal mode and install Adobe first - then install Mcaffee and run the updates completely. if Adobe is not working make sure to modify the settings of Mcaffee and firewall (enabling adobe).
After everything has been completed successfully make sure to run a complete scan using Mcaffee.
Once everything has been done uninstalled the trojan remover or roguefix which was installed earlier. (it is not recommended to have more than one system security)
I hope this helps - Thank you for your time:
Stephen D.