Nextgen galerry

Hello!
I have a problem in my nextgen gallery
when i am trying to upload image(s) there is a message : there was a problem uploading the file
i have read a lot of forums
i was trying to refurbish my plugins
i was trying to deactivate some plugins
but nothing helped
i am not very familiar in php code so i cant check if the problem is somewhere there
so could you please try to help me with solving this problem! i really dont want to delete this gallery and install new one!)