On startup I have a circle with a slash?

Sounds like you screwed the update ...

Since it is only a few days old, I'd recommend a full reinstall from the gray discs.

 

JUst start it up again a couple of times. Or hold down the on button and reset pram.

 

PRAM means Parameter RAM. PRAM is pronounced "Pee-Ram" (just so you don't get confused)

http://support.apple.com/kb/HT1379

Check out that link.

 

I think PRAM stands for Permanent Random Access Memory

so its essentially a type of RAM that is permanently saved (assuming you understand what RAM (Random Access Memory) to your hard drive.) It saves data scuh as Start up disk... or the system time.

Although ill admit i could be wrong... only reason i can imagine PRAM messsing you up is if it it became corrupted

What I think is wrong is a corrupted upgrade from the restarting you computer during upgrade. Hard restarts (restart where you force the hardware to shut down by holding the power button) during an upgrade is giant NO-NO!

I would have thought you knew that from windows or whatever OS you used to use. (ubtuntu, Fedora, etc.) that you knew better, so just be happy that things still semi-work! =]

you might have to re-install OS X with the grey disks that came with your computer. But if your not ready to do tht I would recomend downloading the "combo updater" and installing that CORRECTLY, that may fix your problems.



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If that doesn't fix your problems, my next step would be ready to blame your hardware (since its a new computer) and from there i would run a hardware test (again with those grey disks that came with your computer)

 

Run Disk Utility from boot disks.

Boot from the system discs and run a Repair Disk from Disk Utility and then Repair Permissions. And if it doesn't seem to fix the problem, you may be looking at a complete Erase & Install of the system. Back up whatever you can/need from the disk.