problems to download the code

My arduino uno board usually has problems to download the code, the computer displays error messages, and i have to disconect the board, close the program and open all again to make it work. It something that didnt never happen before, but in the last days is getting worse.
please give me some advice if you think that you know whats happening.

Try another usb cable or other usb port.
What kind of error message ?

it just say something like 'there were problems to download the code into the memory'

Can you make a screendump of the error messages ? Or copy the text ?
When you see many error messages, the first one is the most important.

okey, i will send the next time i see it.