HUGE issue with "logical disk manager"

To start with i am trying to change the name or label (C:, D:, E of my drive.
Reason - I have a portable external drive that i use at uni and home, but the computers at uni label it as E: drive where as the pc at home labels it as D: drive. I am unable to rn applications which i install onj this portable drive with the intention of running them anywhere. But some apps wont run due to the labelling confusion and i have to install them again via the internet on the portable drive again on the new pc.

So I am trying the change the name of the CD drive (at home not uni as the i cant access administrative tools at uni and moreover its easier this way) which is currently labelled as E, so that the portable drive can be labelled as E (just like the labelling at the uni). (btw my portable drive is either labelled as D or any other variable depending on whether i have another usb connected or not. If so, the portable drive gets labbeld differently if connected after the usb, but never mind that)

so i researched online and found that i can change labelling in disk manager.
source - http://www.dougknox.com/tips/xp_drive_letters.htm

However, i cant access the "logical disk manager".
Error - "the dependancy service or group failed to start"
Error - unable to connect to disk manager service

So i searched again and followed the advice on this thread
http://www.tomshardware.co.uk/foru [...] ve-manager

Specifically the post which states the following,
"Logical Disk Manager service depends on Plug and Play service and Remote
Procedure Call (RPC).

Make sure that both are set to Automatic and started.

Open Services...
Start | Run | Type: services.msc | Click OK |
Scroll down to and double click Plug and Play |
Set startup type to Automatic | Click Apply |
Click the Start button | When Plug and Play starts click OK

Repeat for Remote Procedure Call (RPC), Logical Disk Manager.

Scroll down to and double click Logical Disk Manager Administrative Service
|
Set startup type to Automatic | Click Apply |
Click the Start button | When it starts click OK |
Close Services"




THE PROBLEM
See the screenshots below

I cant click the start/stop/etc in "plug and play" or "remote procedure call"dialog boxes





But i can click on the start button in the "logical disk manager" dialogue box but when i do i get the error in screenshot.
"could not start the logical disk manager service on local computer" error 193:0xc1



btw - i m on xp sp2 with vista look.

HELP please !

Been asking people for their help for ages now to no avail.

Have you had a look at the event logs to see if they give you more details of the problem?