photos not transferring to computer... help?!

[xnimporte]

i have over 2000 photos on my unlocked iphone and when i try to download the pics to my pc with 'microsoft scanner and camera wizard', an error message pops up and reads "the scanner or camera is in use. please try again later". i usually go to my computer-->apple iphone-->right click-->get photos. my computer and itunes recognizes the phone and a window titled 'apple iphone' usually pops up saying 'camera connected. select program to launch for this action' but the list is blank..

&this method worked fine a few months ago, when i had around 200-500 pictures, but now it's acting all wonky.. anyone have any remedies?? please help!!!