Purchase and install W7

I have a Toshiba Satellite P105 laptop, ca 2006, running XP3. It works, but there are problems. I would like to purchase and install Windows7. Where is a good place to buy (online is good). I looked at NewEgg, but they are offering a supplier's version, and it looks like you need special software to install. I'm not too techy, as you can see. What I want is a CD that I stick in my drive and say go. I assume this machine will handle W7. I'm also assuming it would require the 32-bit version. Right?

Welcome
Run the Microsoft Windows Upgrade Advisor. Get it from the Microsoft site. This will tell you if you can upgrade to Windows 7 and what drivers will be needed (that's the hard part).
To make susre everyone understands - Microsoft no longer sells media or licenses for the retail version of Windows 7. Tiger Direct and NewEgg have the OEM license. for ~$140. The end of October is the current cutoff for all retail/OEM versions except Professional as I understand it.
There are a number of Windows 7 laptops available "new in box" from HP and Lenovo at very attractive pricing. Other vendors may also have them. We just bought a nice one on Amazon. Worth considering and also converting the current machine to Linux if you want.
Just my 2 cents.

I'm still a little confused. I think there are some problems with my whole installation. I attempted to reinstall the original XP from scratch (with the Toshiba disc), but it wouldn't work (even though it is only possible to reinstall with reformat). Some programs won't work at all (Adobe 10, Google Earth), so after screwing around with this for awhile, I am entertaining a complete reformat and then installing W7. I have done this beore, using the Toshiba disc, but now that doesn't work. NewEgg offers W7-32 for $99, but says it needs an installation program. Do I have to buy that, too? My hope would be to reformat, insert CD, and hit "GO", with maybe some custom installation to omit programs I don't want. Appreciate your replies.