This is just a slightly more detailed mini guide to run multiple instances of ProtoShare Client in windows. Credits to FreeTrade who posted the how-to in https://bitcointalk.org/index.php?topic=325261.0.

Example of ProtoShare client location
-------------------------------------
C:\Program Files (x86)\ProtoShares

Default data directory location
-------------------------------
C:\Users\Username\AppData\Roaming\ProtoShares

Steps
-----
1) First create a protoshares.conf file. Create a new .txt file in C:\Users\Username\AppData\Roaming\ProtoShares and rename to protoshares.conf

Edit protoshares.conf with notepad and insert the following without the (description):

port=3888         (Default protoshare port)
gen=1            (Gen=1 will cause the client to start mining upon launch)
genproclimit=x      (x is the max number of threads with win32 client; Also ram dependent)

2) Next I duplicated C:\Users\Username\AppData\Roaming\ProtoShares directory and created C:\Users\Username\AppData\Roaming\ProtoShares2, so now I have two data directories:

C:\Users\Username\AppData\Roaming\ProtoShares
C:\Users\Username\AppData\Roaming\ProtoShares2

I deleted the wallet from ProtoShares2 directory because I wanted a separate wallet. Inside ProtoShares2 directory, edit protoshares.conf with notepad:

port=xxxx         <= Must change this to another port address e.g. 3889
gen=1           
genproclimit=x

3) To launch ProtoShares Client:

1st Instance - Execute "C:\Program Files (x86)\ProtoShares\protoshares-qt.exe"   (As normal just double-click)
2nd Instance - Execute "C:\Program Files (x86)\ProtoShares\protoshares-qt.exe -port=xxxx -datadir=C:\Users\Username\AppData\Roaming\ProtoShares2"

You can use a shortcut or .bat file to launch the 2nd Instance.

Hope you find this useful. Good luck.