TLE PT 1

Windows XP
Whistler
Window Vista
Pentium 233-megahertz (MHz) processor or faster (300 MHz is recommended)
At least 64 megabytes (MB) of RAM (128 MB is recommended)
At least 1.5 gigabytes (GB) of available space on the hard disk

Then

Windows 7
Vienna and Blackcomb
Windows 8
ndows 7 system requirements
1 gigahertz (GHz) or faster 32-bit (x86) or 64-bit (x64) processor*
1 gigabyte (GB) RAM (32-bit) or 2 GB RAM (64-bit)
16 GB available hard disk space (32-bit) or 20 GB (64-bit)
DirectX 9 graphics device with WDDM 1.0 or higher driver.

Windows Server 2008 R2
Centro
Windows 7
1.4 GHz x86/x64 or Itanium 2 processor.
512 MB RAM (2 GB recommended)
Super VGA or higher display.
32 GB disk space (10 GB for Foundation Edition)
DVD drive.
Keyboard and pointing device