If you need to generate random numbers for your tests then you need to install a free program like Doom Alert.
Doom Alert generates random numbers (between the numbers you indicate) and saves them in a TXT file. You can specify if it generates a new number every second, minute, hour, day, etc.
From the resulting TXT file you can generate statistical graphs using the accumulated data.
To work correctly you need to previously install
NET Framework 1.1 or later.