Am I able to install OSX update within a windows partition?

Question

Earlier today, I restarted my computer but unfortunately, I got the circle with a slash through it. I did a bunch of research on the matter and tried everything. I tried booting to recovery and booting to safe mode to repair my permissions but nothing worked.
I also looked into recovering some of my files that I hadn't gotten the chance to back up which included a variety of options that didn't seem to work either.
Then out of pure curiosity, i booted to my windows partition and lo and behold, I got in. I was also able to access all my data from the mac partition. So i went ahead and backed up everything that needed to be.
I have a friend that's been helping me with this and he said that it may be because the OSX partition header is bad rather than the harddrive header. He then asked if there was a recent update that may have something to do with this? Either way i have no idea. So my question is; If there was an update that i didnt get that perhaps caused this, am I able to install it through the windows partition?
Thanks-

Answer 1

Did your computer come with installer discs? Or, do you have a retail Snow Leopard DVD? If so, then:
Clean Install of Snow Leopard
Be sure to make a backup first because the following procedure will erase
the drive and everything on it.
     1. Boot the computer using the Snow Leopard Installer Disc or the Disc 1 that came
         with your computer.  Insert the disc into the optical drive and restart the computer.
         After the chime press and hold down the  "C" key.  Release the key when you see
         a small spinning gear appear below the dark gray Apple logo.
     2. After the installer loads select your language and click on the Continue
         button. When the menu bar appears select Disk Utility from the Utilities menu.
         After DU loads select the hard drive entry from the left side list (mfgr.'s ID and drive
         size.)  Click on the Partition tab in the DU main window.  Set the number of
         partitions to one (1) from the Partitions drop down menu, click on Options button
         and select GUID, click on OK, then set the format type to MacOS Extended
         (Journaled, if supported), then click on the Apply button.
     3. When the formatting has completed quit DU and return to the installer.  Proceed
         with the OS X installation and follow the directions included with the installer.
     4. When the installation has completed your computer will Restart into the Setup
         Assistant. Be sure you configure your initial admin account with the exact same
         username and password that you used on your old drive. After you finish Setup
         Assistant will complete the installation after which you will be running a fresh
         install of OS X.  You can now begin the update process by opening Software
         Update and installing all recommended updates to bring your installation current.
Download and install Mac OS X 10.6.8 Update Combo v1.1.