You may want to print this page before proceeding so you can refer to it during installation and setup.

Step 1:

First create a folder, Prime95.

Then click on the button and download the Prime95 program into that folder:   


Fill in your name or a pseudonym in Your Name field. You may also leave this blank if you like.

If you want to receive a sporadic newsletter (I've received only one in three years), type your email address in the next field. Try it, you might learn something!

The next two fields must be filled in exactly as shown, because it's case sensitive. Just copy-paste what's below.

Your User ID: WileECoyote Your password: genius

In the field marked Your Computer ID, type in your first initial and last name, like jdoe.

If you do not want to give your name, use a clever pseudonym instead. Please do not use a pseudonym if you are doing this for extra credit, because I will not know who to give the extra points to. Should you leave this field blank, the server will give you a random Computer ID.

Leave the last check box UNCHECKED, you're joining Team Wile E. Coyote!

Then click on OK.

Step 3:

Now we proceed to the CPU settings.

For the top field, enter your best estimate on the number of hours per day your computer is turned on.

Accept the rest of the settings and click on OK.

Step 4:

This next box is used to pick the type of work you want to do.

Leave the Use PrimeNet box checked.

If you use a dial-up (modem) connection, check the next box. Otherwise leave it blank.

Then put in the number of days of work you want to have queued up. I suggest entering 10 in that field, because sometimes the server goes down.

Now we have the work type.


First, uncheck the box marked Request whatever type of work makes the most sense.

Check the box marked Request Mersenne numbers to double-check if any of the following are true: 1. You are doing this for extra credit in my Math 1070, Math 1500, Math 2410, or Math 4130 classes. 2. Your computer is slower than 1.5 Ghz. 3. Your computer is not on very often.

Check the box marked Request Mersenne numbers to run primality tests if either of the following are true: 1. Your computer is faster than 1.5 Ghz, and it is on most of the time. 2. You want to maximize your chances of finding the next Mersenne prime.

Check the box marked Request 10,000,000 numbers to test if both of the following are true: 1. Your computer is faster than 2 Ghz, and you never turn it off. 2. You are very patient. (Testing just one exponent can take over two months)

Now click on OK and you are up and running!

Prime 95 will chug away in the background while you do other things. It is set at the lowest CPU priority, so it will not interfere with your other programs.

Step 5:

Let's fine-tune your setup. If you click on Options on the menu bar and then select Preferences, you will see this:


Accept all the default settings except for one. In the field marked Days between sending new end dates, enter 1.

For people with a direct internet connection, your computer will check in with PrimeNet every day.

For those with dial-up connections, Prime95 will not initiate a connection to the Internet. It will instead check in with the server every day you connect to the Internet, however often that is.

Click on OK.

Minimize the window, and a red Prime 95 icon should appear in the lower right corner of your taskbar. (Do not x or close the window, that will close the program too!)

Step 6:

Check to make sure that the computer ID you entered in step 2 appears on the page here. If it is, then welcome to our team!

To those of you seeking extra credit: send me an email with your name, the number of your class, your UserID, and the names of your computer(s).

You can learn all about the GIMPS project here: 

          Our team ranking is here. Think we can crack the top 20?