Upgrade Windows 7 Starter

I recently bought a HP Notebook with Windows 7 starter installed. What will be the best cost effective way to upgrade to either Windows 7 Home or Premium. I have heard so many stories about problems experience during upgrades especially on HP, with pre-installed software.

Your advice will be appreciated.

HannesB

Take a look at this:
Windows Anytime Upgrade - Upgrade your Windows 7 edition - Microsoft Windows

No install files needed.
Only the Upgrade key is need.
Anytime upgrade only adds-on the Programs & Features from version to version.
http://www.sevenforums.com/tutorials/95744-windows-anytime-upgrade-how.html