Quick Guide for the use of computers at the department

Rooms and Appliances

The workstations at the Department of Computer Science can be found in rooms B221, BK107, CK110 and on the second floor corridor. Log in to computers in rooms with 24h access DK108 and DK110 using the AD-HY account from the Center for IT. You may use any computer in a computer classroom, unless teaching has been scheduled in the room.

The operating system of each workstation in the computer classrooms is Linux, and most computers run Microsoft Windows 7, as well. The operating system can be changed as follows:

To shut down the currently running operating system

  • In Windows, press Ctrl-Alt-Del, click on red up arrow on lower right hand corner and choose "Restart"
  • In Linux, click "Reboot to Windows" and choose Yes (or restart the computer from the lower right hand corner menu)

Choose the operating system you want to use from the startup menu (Linux is the default).

Information on the computer classroom facilities.

The Computer Science Department has several servers of its own, some of which can be used interactively, such as melkki.cs.helsinki.fi and melkinpaasi.cs.helsinki.fi. They can be contacted through ssh with the command ssh username@melkinpaasi.cs.helsinki.fi.


The Linux system makes a difference between upper and lower case letters in the password. You can get a terminal window for input of the commands by pressing Ctrl-Alt-T. Command "exit" closes the terminal window. The working session is ended by choosing "Log Out" from the menu opened by clicking the upper right hand corner. The most popular programs can be found from the menu bar under Applications.


The same username and password are used in Windows as in Linux.

In the computer classes, the Linux home directory is shown as disk drive H in Windows.


The Department of Computer Science user account password is changed on web page https://www.cs.helsinki.fi/passwd. A good password has at least 12 digits, containing upper and lower case letters as well as numbers and special characters. It should not be a word in any language, since programs decoding passwords use a wide range of dictionaries and know how to combine words, as well as recognizing words written backwards. Names, social security numbers and special leisure activity terms are the worst passwords. However, you should be able to remember your password without having it written down on a piece of paper. You should no use the "Save password" service offered on the Web to save passwords from the university computer systems. This is prohibited in the rules for use of the university computer systems, section VI.4.
Please remember that a single user may endanger the security of the whole system with an inferior password.

Keep your password SECRET! Do not "lend" your password to anyone; you are responsible for EVERYTHING that has been done with your account.

The changed password is propagated to all computers of the department at once, except for the mailserver, which is updated twice in an hour (xx:15 and xx:45).

Please remember to change your password at least every 12 months.

The Center for IT AD-HY account password is changed on page http://www.helsinki.fi/atk/adsalasana.


In the Computer Science Department's system, e-mail addresses take the form Firstname.Surname@cs.helsinki.fi.
At the Center for IT, they take the form Firstname.Surname@helsinki.fi.

The university is large, and it cannot be avoided that there will sometimes be several people with the same name. Their addresses are usually distinguished from each other by inserting the first letter of a second name between first name and surname. The addresses given by the IT Department and the CS Dept. may be different, so you should not try to guess e-mail addresses.

You will find the department's e-mail addresses on the department's Web pages.

Co-use of the Center for IT system

Students with computer science as their major subject have two user accounts; one for the department's own system, the other for the Center for IT's services that are common to all the departments of the university (ad-hy account).

Once the Center for IT ad-hy account expires, the CS Department account will expire also. Therefore, renewing the ad-hy account keeps the cs account also alive.

There is a separate e-mail address, home directory and password for each account. The user is identified as the same by a username that is the same in both systems.

Additional Information

25.11.2013 - 18:13 Pekka Niklander
21.09.2009 - 11:40 Webmaster