You can use ZENworks 11 Asset Management with ZENworks 7 Desktop Management installed in your environment.
If you enable ZENworks 11 Configuration Management or ZENworks Patch Management Agent features (in ZENworks Control Center, Configuration tab > Device Management > ZENworks Agent), you are prompted that the ZENworks 7 Desktop Management Agent will be uninstalled.
The ZENworks 11 Configuration Management Agent features include the following:
Bundle Management
Policy Management
Image Management
Patch Management
Remote Management
User Management
Do not enable these features if you want to continue using ZENworks 7 Desktop Management in your environment.