Parallels Service preferences include memory, network, default virtual machine folder, and some other settings. The following describes how to modify the memory and network settings as a demonstration of the handle usage. 

First, you have to obtain a handle of type PHT_DISP_CONFIG by making the PrlSrv_GetCommonPrefs function call. 

To make the memory modification:

1. Call PrlSrv_CommonPrefsBeginEdit to mark the beginning of the operation.
2. Call one or more of the memory management functions from the PHT_DISP_CONFIG group to modify the desired settings.
3. Call PrlSrv_CommonPrefsCommit to save the changes to the Parallels Service configuration.

The network adapter changes are performed outside of the begin/commit block. To modify an existing or to create a new virtual network adapter, use the following steps:

1. First, obtain a handle of type PHT_DISP_NET_ADAPTER by calling the PrlDispCfg_GetDispNet or the PrlDispCfg_CreateDispNet function. The first function obtains a handle to an existing adapter and is used when modifying an adapter. The second function creates and returns a new handle and is used when adding a new virtual adapter to the Parallels Service configuration.
2. Populate or modify the necessary network adapter properties using functions from the PHT_DISP_NET_ADAPTER group.
3. If you are creating a new adapter, call PrlSrv_AddNetAdapter to add the adapter to the Parallels Service configuration. If you are modifying an existing adapter, call PrlSrv_UpdateNetAdapter to save the changes. If you would like to delete an adapter from the Parallels Service configuration, call the PrlSrv_DeleteNetAdapter function.