If you have been using VMWare for a while you'll end up having space problems.
Either your virtual machine disks are TOO big or TOO small.
To handle that VMWare Workstation has a tool (Notice that VMWare Server does not have it)
Called vmware-vdiskmanager.exe (Virtual Disk Manager you can google it with "Virtual Disk Manager vmware")
you will find it in C:\Program Files\VmWare WorkStation\

to Expand a Disk you just do vmware-vdiskmanager.exe -x 40GB mydisk.vmdsk

To Shrink files there are more steps to take. You must remove all snapshots if you had any. Then start the virtual machine, and install the vmwareTools and once you have installed then you go to the control panel Click in Vmware Tools and use the Shrinking features.

Then you can use the vmware-vdiskmanager.exe -k command.

You can find more details intructions in the VMWare site! Good Luck