Connected characters in Photoshop, GIMP and even Notepad

Hello!

Lately, Photoshop, GIMP and even MS Notepad connect  letters (for instance "f" and "i") in various fonts (Myriad, ...). Even  though I only operate Vista computers, this issue does not occur on  other computers.

In the screenshot below you can see Myriad Pro font and the "fi" in the text seems to be too connected. As said, occuring in GIMP and notepad, too, however, not on other machines.

This  is really crazy. Anyone had this before? Could someone help me, please? Thanks in advance,  Erich!