cdi, step 5 isn't impossible, if you don't have any partitions you don't have a hard drive. Every drive has at least one partition.
I have to disagree with Adobe's recommendation. Allowing the page file size to vary can and will cause fragmentation on the drive the page file is located on if page file requirements exceed the minimum size specified. The idea was valid back in the days when 512Mb was a whole lot of RAM and a 1'Gb hard drive was a large drive. In the present, with most folks running LR and/or PS on at least 2Gb of RAM, the page file size has become almost a non-issue. Disk space is cheap and lots of RAM has become the norm. Setting the page file minimum and maximum size to the RAM size and keeping it fixed is not even a noticeable resource drain on a 2''Gb hard drive. And most of us run a lot more than that.
For example, I have 4Gb RAM installed on my XP Pro 32-bit system. The OS sees 3.12Gb of that, my page file is set at a min and max of 4'96 Mb. I have never seen the page file utilization reach 1Gb. And I've watched it on a lot of programs, including CS3 and AutoCad while running some pretty memory-intensive routines. Actually, in my experience, Nikon's Capture NX seems to be the real resource hog, using up to 9'' Mb regularly. Most of the stuff I do in LR and CS3 runs the page file at a max of 5''Mb, plus or minus.
The most important thing to do is set the Page File to the same setting for minimum and maximum. That way you avoid changing the actual file size on the disk and the resulting fragmentation and performance hit. You can start off with twice the RAM size, run some memory-intensive apps and watch the Page File Usage display in Task Manager. If usage is maxing out the size you've set, make it bigger. If not, you can just leave it alone or make it smaller. With disk space as cheap as it is today, there's no real benefit in spending time tweaking it down, if you can't max it out at twice your memory size just leave it there.
My apologies for getting sidetracked on the VM thing, to answer your original ? I don't think there's anything in the LR preferences that allows you to choose memory allocation. Although it's readily available in CS3, LR doesn't seem to have that option. Maybe Melissa will pick up on this, and you can always put in a Feature Request at the Adobe site.
HTH,