If I erase and sync my iTunes library on my iPhone will I also lose my pictures that are on iCloud? My hard drive failed on my computer and I can’t retrieve the original iTunes library. I lost all my music and photos that were saved on the computer as well. I still have 190 photos on my camera roll and about another 500 photos on iCloud.

I want to add new music to my iPhone, and was able to transfer the existing music to my new computer, but I’m having trouble transferring the photos from the iCloud albums to my new computer. I have Windows XP on my current computer so I can’t download the iCloud control panel and use that.

If I erase and sync my iTunes library, with my new library will I still have those 500 photos that are in my iCloud albums?
The photos won't be deleted from iCloud, as re-syncing your device won't delete, nor reset the Photo Stream. 

Photos are deleted from the Photo Stream just by selecting the one you want to get rid of and taping the trash can icon, on iOS, or clicking Delete on the computer. There is, too, a Reset Photo Stream button in you account at iCloud.com.

Just keep in mind that photos are stored in iCloud for 30 days.