Firstly, I play PWI which is installed in my C:drive, and has the PWI patches updated weekly. To play LMS and maintain both versions, I used my external drive and instead the LMS patches there, as well as another copy of Perfect World International Client Setup.
If you don't have your installation setup for the PWI MMORPG, you need to download the setup. Whether if its PWI or LMSPW, it uses the same first setup.
Once you have downloaded it, extract it. Extracting and installingare two different things. After extraction, a folder named "perfect world international" would be created. Open it, and double-click on "install.exe". This will install Perfect World onto your computer. It will create a folder called "Program files", inwhich there would be a "Perfect World Entertainment" folder, followed by "Perfect World International" and within that there are more files now.
Choose where you want it to install - I chose my external-hard drive E-drive, and it will start installing.
You have to download the newest patch and also the animation patch of LMS inorder to be able to play.
I extracted the "animation patch" first, and it asks you wher you want it to be extracted. It is defaulted to a folder named called "LMS", but instead I made a new folder called "animation patch" just to see what files it would give me after extract. I made the folder on the desktop.
Now extract the patch. It again asks you where you want to extract. I made another folder on the desktop and named it "patch ___" woteva version it is.
I opened up the animation patch folder, and fold a folder called "element" and it only had the model.pck file. Cut it, and paste that folder into the Perfect World International folder WHICH IS INSIDE -> PROGRAM FILES -> PERFECT WORLD ENTERTAINMENT.
Do the same for the 'patch' folder, and paste its data into the same folder.
To launch LMS, click on "START LMSPW100x".
Hope this helps!