This might sound like a tricky one to fix because it hasnt actually shown the real error message, just the very unhelpful "server application unavailable". 

But you can usually find the real error message in your windows event log, look in your start menu - control panel - administrative tools- event viewer- application.  There will be lots of entries there, so look for one with a red "x" that says "Error" and "ASP.NET".   If you run your website and then open the event log immediately, it will be at the top.

Once you get the error message from there, please post it here.

I do actually remember seeing something posted about a skin causing "server application unavailable" a while ago.  You can try reverting back to the default skin to see if it is a problem with your skin.  Just find the skin folder, probably in  /portals/_default/skins or /portals/0/skins, and rename it (myskin -> myskin_ will do).  Then the default blue skin will load again - and if your website works, it was something wrong with the skin.

JK.

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Where did you get that error message from? If you can get it from the windows event log, you should see something like this:

Event code: 3005
Event message: An unhandled exception has occurred.
Event time: 17/03/2008 1:49:41 p.m.
Event time (UTC): 17/03/2008 12:49:41 a.m.
Event ID: 8e61c9049147470aa11b9d4d005b5209
Event sequence: 2
Event occurrence: 1
Event detail code: 0

(full exception message follows the above header - please copy and paste your full error msg)

For example, a quick google search for "aspnet_wp.exe (PID: 2828) stopped unexpectedly" shows someone who posted this error message:

Event Type: Error
Event Source: ASP.NET 1.0.3705.0
Event Category: None
Event ID: 1003
Date: 4/24/2002
Time: 6:18:23 PM
User: N/A
Computer: <ComputerName>
Description:
aspnet_wp.exe (PID: <xxx>) was recycled because it was suspected to be in a
deadlocked state. It did not send any responses for pending requests in the
last 180 seconds.

So if you can find the full error message we will have a much better chance of seeing what has really happened.

Yes, you can try renaming the skin folder - I suggested that because you said you had just changed skins when the problem occurred.  It may or may not be the reason for the problem.  If you rename the skin and the problem goes away, then yes it is probably your skin.

JK.

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