my photos in my album dissapeared after the ios8 installation

Which album is missing?

Your photos are probably all there. You have to look in different places.

The new Photos.app has no longer a Camera Roll and a "My Photo Stream" album.

Now all you have to view your photos are:

• The "Recently Added" album in the "Albums" section with all photos added during the last month from anywhere, including your Photo Stream. This view is nice, because it gives a list of all photos, uninterrupted by too much white space, but only the last month of photos.
• The "Photos > Collections" view showing all photos by year or Moments, organized by place or date, with plenty of white space and miniature thumbnails.
• The Shared section with your shared photo streams.

So your photos are all there, but mixed. Apple is hiding where they are stored, if in a Photo Stream or on your device.

Note: older apps can only access the "recent" section or albums. If you want to share photos from other apps, add the photos to an album.

You're welcome! 🙂

- and, you can't erase unwanted pics in the photo stream from your iphone any more.

If they are in the Recent Activity album you can erase them and they will be removed from the My Photo Stream on your Mac.

If they are in the Recent Activity album (on your iPhone) you can erase them (on the iPhone) and they will be removed from the My Photo Stream on your Mac.

You don't need to do the deleting on the Mac if the photos are in the Recent Activity album on the iPhone.

- and, you can't erase unwanted pics in the photo stream from your iphone any more.

If they are in the Recent Activity album you can erase them and they will be removed from the My Photo Stream on your Mac.

"Recent Activity"? Do you mean "Recently Added" album or "Activity" album, OT?

Erasing from "Recently Added" will erase it from the iPhone as well, does't it? I could not find a way so far, to only clear "My Photo Stream" on the iPhone, while keeping the photo on the phone. And "Activity" is only showing my Shared Photo Streams.

I am afraid, we need to delete on the Mac, if we want to delete only from the Photo Stream.

Since downloading ios8 I have lost all of my "camera roll" pictures. They are in the cloud, but now I see that I must have at least windows 7 to sync with the cloud. I have windows vista. Is there any way to recover these photos to my phone?

Yes, deleting it from Recently Activity does delete it from the iPhone as well.

Also deleting from the My Photo Stream on a Mac will delete it from the iPhone if it is in the Recent Activity album. If it's in Moments then deleting from the MPS on a Mac will not remove it from the iPhone.