After literally days and days of trial and error, I have finally managed to get an honest-to-God working dual boot system up and running on my Toshiba Satellite L505. I ended up having to use the 10.5.5 distribution of iDeneb, even though I have a paid-for retail Snow Leopard disc.

Very briefly, I used GParted to partition the single HD into two partitions, then installed Leopard, then installed Win7, then installed EasyBCD to make dual-boot happen. I am now able to boot into either Win7 or OSX without CDs, DVDs, or USB sticks inserted. Hallelujah, holy crap.

So, my question is, can I now use my retail Snow Leopard disc to upgrade the 10.5.5 installation, or is that going to hose up a week's worth of head scratching and disc-spinning?

Thanks in advance for any help you gurus can offer.

Have been advised on another forum that using the retail SL disc to upgrade the iDeneb distribution is not feasible. Unless someone here has a second opinion, I guess I'm off to plan B.