Brand new laptop not right from the start

Ok, so here is an update on my situation. I ran the memtest for 7 passes like suggested and no problems were found. Also the computer has been runing perfectly since I started this post (Like taking a car to the shop and that strange noise stops when you pull into the lot, LOL).
To rephrase my original post, I had the problem a few months after buying it, did the FIRST reformat, then fine agian for another few months until the problem started again. Then I reformatted AGAIN, but this time, as already suggested a little earlier in this thread by gregrocker, I did use a "clean copy" of windows to install, not any restore disks. I may have jumped the gun a little on my first post saying that the problem started right away. Let me explain...
Upon the clean reinstall, after completion, everything was fine. I went to bed and overnight I guess the computer went into hiberantion. It took literally about 15 minutes to come out of it, which I assumed was just the original problem acting up again, so the nI started this post, but have not had any problems since then. BUT then again the last time i did a reinstall, it took a few months to act up again. Hopefully the clean install did fix any problems, and that waking up problem was just some kind of first time install glitch. I have since been using the computer to its extent, and trying to make it fail, but no such luck (which is actually a good thing). So, I guess its fine for now, but I'll let you know if the problem returns.

I do have one more question though. Like I said before I did a clean install from a Windows 7 DVD, but my problem is that the COA sticker on the back of my laptop is for Windows 7 Premium, and what is installed now is Ultimate. I did not know there was a way to unlock which version you wanted to install at that time. I have the 30 days to activate the Ultimate but no key. I was just using it as a test and didn't think ahead to figure out what to do if it actually worked. I dont mind purchasing the upgrade, but how exactly would that work, since "technically" i did a full install of ultimate, and not an "upgrade" from premium? And who would I call to obtain the Key? And what would the cost roughly be?