Unable to login to Zorin OS

Extremely new to Linux. Only a month or so experience. Used all last nite with no problems. Turned on this morning and it booted to the zorin login screen. This never happens as I have auto login enabled. I enter my password and it keeps looping back to enter password. No invalid password errors so my password should be ok. I am unable to login with guest either. Same looping back too. I have always had trouble with shutting down. The hard drive would power down but the pc fans would stay running. 3 out of every 5 times at least. I added acpi=force apm=power_off after quiet splash in the grub. All has been fine for the past few days untiI now. What to do????

Hi, is this a PC or a Notebook?:

viewtopic.php?f=5&t=5449

Did you follow Wolfman's excellent post-install guide?:

viewtopic.php?f=5&t=2054

I would be tempted to reinstall - if you have any data on the drive boot using your Zorin DVD and copy your '/home' folder to a USB thumb drive, remembering to press Ctrl+ H to show any hidden files.

Keep us posted!

PS For peace of mind, I would not setup any machine with autologin as it makes it less secure - especially if it were stolen!

Sorry, this is a pc. Zorin 9 is the only os installed on a 1tb hd. Win 7 installed in virtual box just to run quickbooks and acrobat for the time being. Thank you for the two links. I did not follow Wolfman's guide. I had found the link after the initial install. Copying files now for possible reinstall. Really don't need anything except .thunderbird. Everything else is stored on an external nas. Really looking for a fix. More so for the learning curve. Hate taking the easy way out and reinstalling but that looks like the route I'm might have to take. Will post updates.