Cant find instant message on my mac book pro

Question

im running snowleopard on my mac book pro and i cant acess or find my instant messaging, no icon, and cant find it in finder or anywhere??? i bought it in 2011, its actually my sisters, my 2009 MBP works fine, any answers out there?

Answer 1

In answer to your second question, it wouldn't matter much on your sister's MBP, as Snow Leopard doesn't support iCloud for messaging (or for much of anything, though you can force a few things). Her iChat is limited to AIM instant messaging and such.
On your MBP, which according to your profile is running Lion (10.7.5), you also won't have access to iCloud messaging (iMessage) unless you installed the beta-test iMessages application and somehow kept it running. (I have heard it can no longer be installed and may no longer work at all. That's third-hand; I haven't tried it.) Your iChat will also be limited to AIM and such.
For those with iMessage-capable phones and computers, there is a choice to be made. Apple's apparent concept for iCloud would suggest that you would use a single iCloud account for all of the devices you individually own or use. (I do that; my wife does also, with her own ID.) That model works well when, for example, you want to receive all the same iMessages on all of your devices. Even if you don't, there are ways to keep them separate (e.g., use the phone number to send/receive iMessages on your iPhone while using an email address on the MBP).