You can host multiple office component in a form or you can open multiple office instance in your internet explore with Edraw Office Viewer Component version 7.

For the previous version, The component won't work for the IE8 and the Office 2007. The toolbars will be uneditable if you put the component in IE8. Then open multiple instances from different IE table. The other office instance can't be edited except for the last opened office instance. If you launch a word or excel program from the destop, the error will occur too. All the Excel documents opened by DsoFramer share only one Excel process. The result is when the second Excel document opened by the DsoFramer, the first document is uneditable.

Note: you need set the Frame hook policy as SetOnFirstOpen and Component activation policy as KeepUIActiveOnAppDeactive.

Frame hook policy

To correctly handle activation when the host gains or loses foreground status, the ActiveX control uses a frame hook. By default, the hook is set when the control is created. In some situations, especially when the control is used from a multi-threaded UI host or when the control is nested in a container control like a Tab page in a .NET WinForm application, the parent of the control at create time may not be the correct window for the control to hook when it is running. In these situations, you can use the FrameHookPolicy property to reset the hook at a more suitable time. For example, if you build a .NET WinForm solution, set the FrameHookPolicy property to SetOnFirstOpen in the Properties window.

Component activation policy

The sample control can support more than one instance of itself in a given host application. However, only one control can be active at a given time. This is a requirement of ActiveX Document hosting. To handle multiple instances in a single host, the control registers itself with a component manager. This lets the component manager keep track of the active control. Use the ActivationPolicy property to control how the embedded object is handled during component changes. The ActivationPolicy property can be set to one or more of the bit flags that are defined by the ActivationPolicy enumeration.

You need set it as follow:
param name=”ActivationPolicy” value=”1″
param name=”FrameHookPolicy” value=”1″

Or in your custom user control, set the following properties of the office viewer component: Activationpolicy=4, FrameHookPolicy=1.

But this leads to another problem: the inner office application is reloaded every time the control is activated. So if you can hide some of the toolbar buttons, you have to use the code in the activation blocks instead of the control initialize statement.