You can check hardware compatibility at the Mandriva WEB site:
http://www.mandriva.com/
If you speak English, you can use this URL:
http://www.mandriva.com/en/hardware
Mandriva is Open Source Software, and it is free in the sense that you are under no legal obligation to purchase a license for it's use. By using it you are breaking no laws.
You can get the source code, and make any modifications you want, then freely redistribute your modifications provided you meet the requirements of the GPL.
On the other hand, a great many people put in a great deal of hard work producing this software and they deserve something back for their efforts, so there is a moral obligation to contribute to the Linux community in some way.
It is understood that a new user may not be able to make any kind of meaningfull contribution and that some users may not be able to make financial contributions. It is true however, that all users will at some point in their progress with Linux be able to contribute in some way, whether it be financially, or by joining an Open Source project and helping with coding, generating or translating documentation, or by providing help to newer users as we do here, which I see as being a good will ambassador.
HTH,