For the longest time I've been plagued by a strange bug on my CE 5 x86 German-language device: When installing specific .cab files, sometimes, the typical "folder select" common dialogue would very briefly appear, and then immediately closed again, followed by an error message that the program had not successfully been installed. I've finally figured out what causes this.
Some installers are hardcoded to look for the directory "\Program Files" - which does not exist on German-language CE devices. Instead, those have "\Programme". I've managed to fix the issue by just creating a new "\Program Files" directory. Even though I'm not planning to install anything in that specific folder anyway, I can now run most .cab installers without issues.
I hope this helps in case anyway with a non-english language CE device has been struggling with the same problem!