USB starter with ubuntu 15.04 only works once (1 of 4 questions)

Hi everyone,
I just installed a few days ago ubuntu 15.04 and as it was really slow because of the newer version of the youtube player (by the way how could I get back to the old version??? question1), I tried lubuntu but I really just like too much the mate desktop so I tried to installed it again but the USB starter failed… (by the way, how is it possible that I still need to write “live” so the actual live version starts??question2).
So I had to download the iso file on another computer and reset the usb starter so I could install it again…
Now as I want to install this newer ubuntu mater version on the other computer, same problem again, I had to reset the usb starter to be able to install it.
It is proof that the version can be installed only once… that is really strange no? what can be the cause??? question3
At last, I wanted to check with you if by erasing the disc to install a proper reformat was done (as I have the feeling the timing to access the HD is quite slow and everytime I want to install the ubuntu it takes until 5minutes to bring me from the page where your HD space, internet connection, and electric plus is checked to the page where you choose if you want your previous version erased or not? question4

Thank you dear community for your dedication and for answering my different questions…

now, by trying to install ubuntu mate 15.04 on the other computer (where ubuntu mate 14.4.2 was installed) I get the following error message:
The creatoin of the interchange space on parition #5 of SCSI1 (0,0,0) (sda) has failed (translated from spanish)
why? question 5


did you pre-format the USB stick to FAT32 before you created the boot media?.

See also:

What is your partition layout like?:

The big question is what was used to write the ISO to the USB stick. After a lot of experimentation I have found that the best solutions are:

Linux: use dd if=<iso file> of=/dev/sd<letter of USB stick>

Windows: use ImageUSB.

For Windows, in particular, there are a lot of ISO writing tools which are either overcomplicated or don’t work.

Yes, after formating slowly the usb stick with disk and installing the iso again with the disk creator of ubuntu, I made the live work much better.

dd if= of=/dev/sd

just putting this in the terminal creates the usb starter???


under Debian/Ubuntu based systems; I use Unetbootin: