It would be helpful if you were to post a snapshot of gparted showing your sda drive, as I suspect that your description may not be complete.
Just to confirm, what you want is to make your Windows partition larger, and that sda5 is empty and can be deleted to make it truly unallocated, yes? If yes, then it's possible to do what you want, but I'll caution you... BACKUP BACKUP BACKUP first. Moving data and partitions around can be risky, so be prepared.
I'll also caution you that any time you mess with a Windows partition, it'll probably not boot into Windows the first time without some help. You'll want to have boot-repair, and a Windows install disk ready, just in case.
Based just on what you've told us so far, a brief outline of what you'll need to be prepared to do is:
- install boot-repair (using Synaptic) in Ubuntu (this will be used to fix booting issues)
if boot-repair is not available in Synaptic, you'll have to start the Terminal app from the Dash, and enter the following, as separate lines:
sudo add-apt-repository ppa:yannubuntu/boot-repair && sudo apt-get update
sudo apt-get install -y boot-repair
- start "Boot Repair" from the Dash just to make sure it works, then quit it
- start gparted from the Dash in Ubuntu
- use gparted to delete sda5 and sda1 to make it truly unallocated space
- use gparted to move sda2 all the way to the beginning of the drive
- try to boot into Windows now (and here's where you may have trouble, and may need to use boot-repair from Ubuntu, or use a Windows install disk running in repair mode)
- once Windows is booted, you'll want to start the Disk Management program, and EXTEND the Windows C: partition
Are you ready to do this, or is it too much, too scary? More detail available on request.