More details would be helpful. Things like operating system version, what are you opening (you say "when i open")? In other words, we need a lot more information -- emphasis on the word "lot".
Also, if there is actual text associated with this error message, please quote the exact completed unedited word-for-word error message.
i have mac 10.7.5 and downloading photoshop cc 14 was fine but downloading lightroom 5 stopped and i restarted the computer - then when i try to open it it says error:5 and it doesnt give me the option to uninstall it - i am "opening" it from the cloud -- this is what it says:
please uninstall and reinstall the product
if this problem still occurs, please contact Adobe technical support for help, and mention the error code shown at the bottom of this screen
I don't understand "opening it from the cloud"
You say "... but downloading Lightroom 5 stopped and i restarted the computer", did you actually complete a download of Lightroom 5?
Did you contact Adobe technical support, as advised?