Windows 10 preview is released and you can get it as a Beta version. It is not like Windows 8's Consumer preview. This is being released via a new technology called Insider program that help to get user feedback and even provides forums to discuss errors and spots with Microsoft engineers. Here is a tutorial about the installation of windows 10 using a flash drive.
Minimum requirements that your computer needed is,
- 1 GHz possessor.
- 1GB ram or 2 GB ram for 64 bit version.
- Hard disk space - 16GB
- Graphic card - Microsoft DirectX 9 graphics device with WDDM driver
In addition to this you need to have a flash drive (Minimum 4GB) and you need to download and install Rufus, a free utility software that help to make bootable iso image.