For scanning hardware like your hard drive, RAM, motherboard, etc I use the ultimate boot cd --> http://www.ultimatebootcd.com/ which contains everything you need to troubleshoot and diagnose problems on your computer.
Joe
-----original message-----
>>I don't remember if Ubuntu's LiveCD has this or not, but most have a memory check program as an advanced boot option. If it does just run that program and see if any errors are displayed prior to paying for stuff...>>
[Non-text portions of this message have been removed]
.