Cornflake Addict of neowin forums has a good post on what to do and what not to do while installing windows vista
What NOT to do when installing Windows Vista.
1. Do not upgrade over Windows XP Home or Professional (SP2 must be installed to perform upgrade).
2. Do not install on the same partition as Windows XP Home or Professional (SP2 must be installed).
3. Do not at any time turn off or disrupt the installation.
4. Do not assume that all your software is compatible with Windows Vista because software developers and vendors are working with Microsoft to make your software compatible. (well not all of them but the important ones are).
What YOU should do when installing Windows Vista.
1. Create a separate partition of around 12GB is enough, using Partition Magic and then call it VistaBeta (or whatever you want to call it). Windows Vista needs around 8.5Gb of HDD space to install.
2. Run the installation via Windows XP Home or Professional, when you have the option of which partition you want to install Windows Vista on, make sure you select the new partition you created in step one.
The installation should take approximately 45mins to install (this might be different on older machines). Below is a time list of my installation after my tests.