- Backup your hard drive. All of it.
- Have a Windows installer and an Ubuntu installer ready.
- Install Windows first, than Ubuntu second.
Additional notes to Windows7 installation:
- to be able to change the display language you'll need Win7 Ultimate or Win7 Enterprise.
- download additional language packs from the Control Panel, or directly from this site.
- I gave 40GB space for Windows7 on my hard drive besides Ubuntu. It made 2 partitions out of it, one 100MB large for the system purposes, and another from the rest of the space for the rest of the system.