There are the following protected-mode execution services:
| Service | Description |
| Allocate_PM_App_CB_Area | Allocates application control block. |
| Begin_Use_Locked_PM_Stack | Locks protected-mode stack. |
| End_Use_Locked_PM_Stack | Unlocks the protected-mode stack. |
| Get_Cur_PM_App_CB | Returns application control block. |
| Set_PM_Exec_Mode | Sets protected-mode execution. |
| Set_V86_Exec_Mode | Set V86 mode execution. |