partition the drive...just go to download.com and look up drive partition software and you'll find a bunch. In case you don't know, partitioning your hard drive is simply splitting you hard drive space into two or more sections of smaller space. So specify a partition large enough to hold all 1500 songs and then have the tech guy reformat windows on the partition which is NOT the one you copied your songs too.
As a bonus, this will be better for the performance of the computer down the road. You'll store all your space sensitive stuff on one partition and all your windows, driver and software stuff on the other...so program performance wont be gummed up by music, movies, games etc...