I needed to rescue Amren from Rannveig's Fast. Well I got there cleaned it out and I see no Amren. I popped back out into Skyrim it said he was back in Whiterun. I galloped back to Whiterun..then my map said he was outside White run at a ruins Silent Moons Camp. I am now outside that ruins and I am all over the ruins and inside it. No Amren. I have restarted and re-installed and nothing.

Any help would be greatly appreciated.

Mereinid

That is a radiant quest that can be one of 200 NPCs and be in one of 50 different locations. This comes with a numerous amount of bugs. One, and probably the only chance of a workaround, is to locate the NPCs home. That is IF they even have one. Enter the home and exit it again. This has proven to spawn some that have been lost.

While that is only a small chance of actually working, it is the only one I know of. The only other options are to either advance the quest through console commands (PC) or otherwise revert to a previous save before the quest was given.

That's why you save before do any quest.