There is a problem with Adobe Acrobat/Reader. If it is running, please exit and try again. (103:103)

When you try to view the pdf file from web browser (e.g. Internet Explorer and Firefox), you might encountered error bellow:

It happen on Adobe Reader X (version 10) together with Windows 7 or Vista. Some users claimed that it happen on Windows XP as well.

Solution

1. Lauch Adobe Reader X (run the program itself outside of the Internet Explorer)
2. From the menu, choose Edit -> preferences -> General
3. Uncheck the option for “Enable Protected Mode at startup“
4. Restart the Adobe Reader and web browser.

Alternate Solution

Uninstall Adobe Reader X and install with Adobe Reader 9