You need to install VMware Tools on your vm:
To install VMware Tools in most VMware products:
Power on the virtual machine.
Log in to the virtual machine using an account with Administrator or root privileges.
Wait for the desktop to load and be ready.
Click Install/Upgrade VMware Tools. There are two places to find this option:
- Right-click on the running virtual machine object and choose
Install/Upgrade VMware Tools.
Right-click on the running virtual
machine object and click Open Console. In the Console menu click VM
and click Install/Upgrade VMware Tools.
Note: In ESX/ESXi 4.x, navigate to VM > Guest > Install/Upgrade
VMware Tools. In Workstation, navigate to VM > Install/Upgrade VMware
Tools.
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Source: http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1014294