Backing up photos for PC onto disc?

[Pinkrose1]

I never use my desktop much these days especially as it is sloth like slow.

I need to take it to pc world for a clean up but want to back up my millions of photos.

I tried burning them to a DVD+R disc but it would not accept the disc and I got the usual gobbledygook as an explanation rather than, use this dumbo.

So what disc Do I use?

Tia