Did you download them manually from Apple's site or used Software Update?
Even if you downloaded them manually and it's the wrong one it should give a warning that it's not for your Mac and normally the Installer won't allow it to be installed.
There's plenty you can do before thinking about reinstalling.
Start Up in Verbose mode by holding Command-V at startup, then look where it hangs, write it down and report here.
Start Up in Safe Mode by holding Shift at startup,does this work, if so go on to do the next.
Repair Permissions in Disk Utility and check the disk for Errors also in Disk Utility.
It won't let you repair the disk because the disk is the startup disk, if all is green it is OK, if not you have to restart, Hold Command-S and it will start up in Single User Mode.
You'll see a bit of text on the display, it should automatically repair the disk.
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Read more about this here.)
Type "reboot" or to reboot or mac-boot to start up the System.
Is it solved now?
Oh, and btw, nobody is going to email, just check here.