twistedtree,
The requirements for TZ Explorer are greater than required for TZ Navigator. You are running TZ explorer. Below are the requirements:
■Windows XP, Windows Vista or Windows 7
■2 GHz Processor (Intel Core2Duo highly recommended)
■CD/DVD-ROM drive for installing software and charts
■20 GB of hard drive space for software (up to 5 GB for charts)
■Video card(WDDM driver, Pixel Shader 2.0, 32 Bits/pixel)
■Minimum: Dedicated ATI or NVIDIA card with 256 MB RAM
■Recommended: Dedicated ATI or NVIDIA card with 512 MB RAM
■Integrated Chipsets are not supported
■Screen Settings: 1024 x 768, 16 Bit (32 Bit recommended)
■Serial or USB port(s) for connecting navigation equipment (Adapter required for USB connection)
■Ethernet 10/100 Base-T for NavNet 3D connection
■2 GB RAM
As you can see 2GB of system memory are required for TZ Explorer. When it comes to checking your video ram memory; I recommend using "DXDIAG". Using XP you and hit your start button and click on RUN and input DXDIAG to bring up the program. It will tell you a lot about your system. In Windows 7 you can just hit start and enter DXDIAG in the search box and then click on the DXDIAG result to run it. DXDIAG is a direct X program and I find it very helpful when checking on the specs of a machine. There are other ways to go about getting your video ram info, but this is just one method.
Johnny