Steps to install and run lpsolve on a Windows machine

1. Download lpsolve.

I'll assume you download things to your Downloads folder.

2. Go to your Downloads folder.

You should see a file with a name like

lp_solve_5.5.2.5_IDE_Setup.exe

or

LPSolveIDESetup55.exe

Double-click on this file to run the IDE setup application for lp_solve. You will be asked some questions (such as where to install it, etc.). You can probably select yes/default for all questions.
3. You should see a desktop icon LPSolveIDE that you can double-click to start the LPSolve IDE (it may start automatically when you install it).
4. You should see two windows for the IDE. One is all black, and the other is not: the first one is where results will be displayed.
5. You can enter a simple LP to test things out. In the Source tab of the IDE window, you can enter this LP:

min: x+y;
3x+10y>=20;
50x+7y>=199;
int x,y;

6. Click on the Options tab in the IDE (the small one, in the row Source - Matrix - Options - Plugins).

Then click Messages.
Then next to "Print Sol" select True.

7. Click on the green arrow to run lpsolve and solve this LP.
8. In the window that was originally black, you should now see a bunch of text, including this:

Value of objective function: 5.0000000000

Actual values of the variables:
x                                4
y                                1

You can copy and paste from this window into, for example, NotePad or other text editor.