Hello Mariusz,
Windows 2008 should contain the basic the Intel E1000(e) NIC drivers. However it is possible that there is now some conflict between the driver version that was installed and the one that is present in the current Virtual environment. A few things you could do is:
- Uninstall all available Intel NIC Drivers from the Add&Remove Programs menu in the Guest OS
- Better option in my opinion: Change the NIC driver to vmxnet3 in the vCenter, but beware you'll lose all the NIC settings that way - make sure to note them down before you do this.
- Mouse control might again be conflicting with the driver that is already present from the physical guest OS. Check for all HID compliant devices and all devices under Mice tree and remove them.
Good luck!