RAM DISK drive letter assignment

I am creating a RAM disk to store my browser cache files as to speed up the loading of web pages. The problem I am haveing is figuring out what drive letter to assign to it, here is a snipplet of the instructions I am folowing:

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Create a new temporary directory on the RAM drive to store all browser cache/cookie files, by adding this line to your Autoexec.bat file (example):
MD D:\TEMP

presuming you have only 1 hard disk/partition and 1 CD-ROM drive. Change this letter if you have more drives to the next available letter AFTER the last letter taken by your hard disks/partitions, and BEFORE the CD-ROM drive letter.
DO NOT allow your browser to use the root directory on the RAM drive as its cache folder, because the RAMDRIVE.SYS root directory can ONLY hold up to 512 files, because it uses the obsolete FAT12 (used on floppy disks) as its default File System!
FYI: FAT16 also supports ONLY maximum 512 root entries, and newer FAT32 allows unlimited root entries.

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Ok I have a setup like this:

Pri Master partition 1: Windows, active, bootable, Fat32 C:\
Pri Master partition 2: FAT32 empty, E:\
Pri Slave partition 1:Primary partition, FAT32, D:\
Sec Master, CD-ROM, drive F:\

I am confused about what letter to assign my RAM disk. Any help would be apreciated,

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To the best of my knowledge, the operating system assigns a
drive letter to a ramdrive automatically, and you do not have
a choice. The drive letter will be assigned based on what drives
are already found on the system at bootup.

One small worry can nag you. If you have other drives that
can go offline, or require drivers loaded after bootup, your
configuration could change from time to time.

This means that if you tell a program to use E:\TEMP for
its tempfiles, because you found that E: is your ramdrive
but some other drive goes offline, and next time you boot,
the ramdrive is D:, you could have a problem.

The emergency boot disk in win98 has a ramdrive in it,
where it loads its utilities. Its AUTOEXEC.BAT file is written in a way
to test and discover what letter is assigned to the ramdrive.
You should study it, adapt it or write something like it so
that programs can reliably know the letter of the ramdrive.

Then they will be assured of always accessing the correct drive
instead of making an assumption that may be incorrect.

I made the nessisary additions to config.sys, but upon rebooting, useing windows explorer I dont see a new drive listed. Is it suposed to be visible?