How can i measure voltage on PSU?

[MassacreAL]

my modem is randomly disconnecting, its telling me "insufficient usb bandwidth"(ive got USB 2.0), and i think its becouse my PSU is not good enough to supply modem or usb with electricity. is there any way how can i measure voltages? i was looking for some soft on google but there was nothing. i would be grateful for any help

[Goober]

You have to use a voltage meter with the computer running and probing the top end of the connector at the motherboard. Here is a real good article explaining how to do it.
Read this! (http://www.informit.com/articles/article.asp?p=31105&seqNum=12&rl=1)