Frequently Asked Questions


  • How can I make sure that an e-mail attachment is safe to open?

    Nowadays every attachment is a possible security threat (virus, trojan horse, etc.).
    If you you want to minimize the risk of inceftion we advise to scan attachments before opening especially files from unknown senders or unexspected e-mails.

    You can do that with the free online virus/malware/URL scanner from VirusTotal where the file is checked by the most common an reliable up to date virus-scanners.

    To scan a attachment:

    • save the attachment to a local folder but do not open it
    • visit VirusTotal and upload the attachment


    Interpreting the scan result:

    If only some (or less) out of the nearly 50 scanners say that the file might be harmful it is normally safe to open the file. The more scanners detect a threat the more dangerous it is to open the file. In case you are not sure don't hesitate to contact the helpdesk.



  • I've been asked for personal information via e-mail, on a website, ...


    Be aware if the email

    • comes from an unrecognized sender
    • asks you to confirm personal or financial information over the internet and/or makes urgent requests for this information
    • isn’t personalized
    • tries to upset you into acting quickly by threatening you with frightening information
    • asks for personal information and appears to come from an enterprise you do business with. Phishing web sites often copy the entire look of a legitimate web site, making it appear authentic. To be safe, call the legitimate enterprise first to see if they really sent that email to you. Companies you want to do business with do not request personal information to be sent via email.

    Personal/financial information

    Communicate personal information only via phone or secure web sites: look for a sign that the site is secure such as a lock icon on the browser’s status bar or a “https:” URL whereby the “s” stands for “secure” rather than a “http:”.

    Also, beware of phone phishing schemes. Do not divulge personal information over the phone unless you initiated the call. Be cautious of emails that ask you to call a phone number to update your account information as well.

    Never email personal or financial information, even if you are close with the recipient. You never know who may gain access to your email account, or to the person’s account to whom you are emailing.

    Links, attachments, file download

    Do not click on links, download files or open attachments in emails from unknown senders. It is best to open attachments only when you are expecting them and know what they contain, even if you know the sender.

    Pop ups

    Be aware of pop ups and

    • do not enter personal information in a pop-up screen. Reputable enterprises do not ask you to submit personal information in pop up screens
    • do not click on links in a pop-up screen
    • do not copy web addresses into your browser from pop-ups

    General advise

    • check your online accounts and bank statements regularly to ensure that no unauthorized transactions have been made
    • you should always be careful about giving out personal information over the Internet. Luckily, companies have begun to employ tactics to fight against phishers, but they cannot fully protect you on their own.
    • remember that you may be targeted almost anywhere online, so always keep an eye out for those 'phishy' schemes and never feel pressured to give up personal information online
  • My disc space is full ("quota exceeded")! Or: How can I check my remaining disk space on the network home directory?


    Open the Windows-Explorer and right click on the drive letter and select properties. The window shows how much space is left among other drive information.


    When you issue the disk free command (df -h $HOME) in a command-line terminal, the output does not show the whole disk space available on the NFS-Shares but your quota. I.e. under "Size" you will see your hard quota and under "Used" you will see the amount of space you are currently using.

    Please note: The usual quota command does not work together with our storage system. It will have no output when you execute it.

  • How do I restore files on my own?

    Restoring files on your own only works for the faculty storage which is usually the "u:"-drive on windows machines or the home directory on linux machines.

    Windows (faculty storagespace)

    • Please locate the folder where the file(s) is stored.
    • Right click the folder and select "Properties".
    • Select the slider "Previous versions".
    • Select a version where your file was fine and open it by double-clicking.
    • Copy the file you want to restore and paste it to the folder where you want to store the file (you can also overwrite the faulty file, or simply drag and drop the file to your desktop).

    Linux (faculty storagespace)

    Restoring files can only be done on a Windows computer which is located in the meeting room on the third floor. Please use this computer and follow the above instructions.

    Restoring files from ZID fileservices

    To restore files on ZID storagespace you have to write an e-mail to the ZID-Helpdesk containing following information:

    • name of the file
    • last known date where the file should have been good
    • directory of the file
  • There is a virus/trojan horse warning appearing on my screen - help!

    Please call our hotline (+43-1-4277-50685) immediately to prevent further contamination and possible loss of data. Do not ignore such warnings and don’t try to solve the problem on your own.

  • My printer is paused/disabled/rejects jobs under Linux! How can I activate it to print my job?

    Please enter

    lpadmin -E -p PRINTER

    (replace PRINTER with your printer’s name, normally “followme”). You may view the current printer status by executing

    lpq -P PRINTER

    (or in your application’s graphical printer dialog). If the lpadmin command does not work, please also try

    lpenable PRINTER


    lpaccept PRINTER

    If your printer still refuses to work, please contact the Helpdesk (including your printer’s name and location).

  • How do I scan multiple sheets into one document?

    Note that by default our copiers are configured to wait for additional sheets of paper when scanning using the original glass as if the option “Separate Scan” is on!

    If you put all your sheets into the automatic document feeder, everything will automatically be put into one output file. If you have more than 100 sheets, you have to enable the “Separate Scan” option, see the instructions at Scanning a number of originals ([Separate Scan]) (german).

  • Why is the print quality when printing from a web browser poor?

    If you print a document within a web browser, you might not achieve optimal print quality. It can happen that the printout is blurry, that a font is replaced by another one (of a different size) and that forms look different. Because of this we recommend that you download the file first and then print it with other software.

  • Why does the printer ask for the correct paper size and doesn't print?

    Since the only available paper size at the department is A4 and A3, please do not send print jobs requesting another paper size (if you do not intend to bring this exact paper with you)!

    Thus, choose A4 (or A3) in the printer menu and do not use the option ‘Choose paper source by pdf page size’ in Adobe Reader, since many documents (e.g. research papers) have other dimensions.

  • I need temporary access to a Windows computer/MS Office/Adobe Acrobat Professional...

    In the meeting room on the third floor, there's a Windows computer with Microsoft Office and Adobe Acrobat Prof. installed (in addition to the standard installation). Please feel free to use it. You can log in with your u:account (=mailbox-account).

    For more information on our Windows computers see this page.

  • Which software is installed on my Windows/Linux computer by default?
  • How do I get updates for a managed Windows Notebook?

    Please bring your Laptop at least every 2 months or use VPN to get software updates which are important for the security of your laptop.

    To get the latest updates you have to right-click the "Matrix 42" icon (square with smaller red squares in it, located in the tray icon bar) and select "Check for new approved Software". The Software will download in the background and can take a long time depending on the size. So if you connect from the outside please make sure to have a sufficient internet connection.

    If the software was downloaded correctly and you restart your computer you will see a window showing Matrix 42. Please do not log in and let the installation finish. The installation can take up to an hour depending on the software downloaded before.

  • How can I install other Linux software that I need for my project?
    • If the software is included in Ubuntu Linux (see or "apt-cache search MYSOFTWARE"), please contact the Helpdesk and we will permanently install the software on your PC.

    • If the software is not included in Ubuntu Linux, but there exists a third-party Ubuntu package repository including the software, we may be able to install it. Please send a detailed request to the Helpdesk, at least including the software's name and where we can find it.

    • If the software is not included in Ubuntu Linux and there is no Ubuntu package for it, we don't support a global installation to your PC. You may try to install it to your home directory yourself, so the software will survive reinstallation of your computer.

      Note: One special case is Maple. It is not included on your computer by default (because of a limited number of licenses), but we will install it if you need it. Please send a request including your computer's name (enter "hostname" in a command-line terminal) to the Helpdesk.

  • Firefox/Thunderbird won’t start in Linux because it says an instance is already running - what should I do?

    It looks like Firefox/Thunderbird did not exit correctly last time you used it or an instance is still running in the background.

    Please run from a terminal window. This should fix the problem.

  • Firefox lost all my bookmarks!

    Unfortunately, sometimes Firefox loses user bookmarks when it crashes, or when it gets upgraded to a newer release in the background while still running.

    Usually you can restore an earlier (working) version of the bookmarks yourself: Please open Firefox (if it is not running already). From the menu bar, choose "Bookmarks" -> "Show All Bookmarks". Choose "Import and backup", then under "Restore" you will find a list of dates when the bookmarks were backed up by Firefox. Click on a recent date (the most recent backup will usually be the best option). A dialog will appear, asking if you want to replace the bookmarks. Click "OK" there. Now please restart Firefox and your bookmarks should be available again.

    Under rare circumstances, this procedure does not suffice to restore the bookmarks. In this case, the computer group can restore an older Firefox profile for you from the storage backup. Please contact the Helpdesk (don't forget to include your username, and, if possible, your computer's name, in the request)!