Windows rtl8139 to e1000 switch get curios effekt

May some one knows Help. I just switched the Networkdevice of a Windows-VM (Win2003 Server), wich I migrade from VMWARE to ProxmoxVE 1.4, from rtl8139 to e1000. Know the kuriosum. When I drop the old rtl8139 device in Win2003 the Network isn't Working. But there is no rtl8139 in ProxmoxVE defined any more. When I drop the new e1000 and hold the rtl8139 in Windwos the Network isn't too not working. I think that is not realy a nice looking feature wich may cause some Network issues.

Someone an Idea how to fix this?

Sorry tom that's not the Problem. The e1000 is working with the right and new Driver like explanded in your thread. But when I deaktivate the old rtl8139 Network connection the e1000 isn't workin any more. It's realy curious