WordPress 3.5 HTTP error after uploading picture

Every image uploaded shows: Error abc.jpg HTTP Error.

After a lengthy delay the images are visible on the screen and appear to be uploaded.

I tried deactivating every plugins, without success.

I deleted wp-admin and wp-includes, and replaced them with the wordpress 3.4 files.

It worked, then when reactivated all the pluggins again, I got the same error again.

I deactivated them again, it didn’t fix it.

I went trough the same process again, deleted wp-admin and wp-includes, but and reuploaded the wordpress 3.4 files again.

But this time it doesn’t work.. I don’t get it.