Windows cannot impersonate the user

(Insufficient system resources exist to complete the requested service. ) 
server become inaccessible (no access to shares, Home Server Console, or RDP), although I could still ping the machine.
http://social.technet.microsoft.com/Forums/en-US/winserverGP/thread/1961f079-2092-4ccb-9e70-8d8fb22f8393
1.Click Start, click Run, type regedit, and then click OK.
.Locate and then click the following registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management
3.On the Edit menu, point to New, and then click DWORD Value.
4.In the New Value #1 box, type PoolUsageMaximum, and then press ENTER.
5.Right-click PoolUsageMaximum, and then click Modify.
6.In the Value data box, type 60, click Decimal, and then click OK.
7.If the PagedPoolSize registry entry exists, go to step 8. If the PagedPoolSize registry entry does not exist, create it.
To do this, follow these steps:
•On the Edit menu, point to New, and then click DWORD Value.
•In the New Value #1 box, type PagedPoolSize, and then press ENTER.
8.Right-click PagedPoolSize, and then click Modify.
9.In the Value data box, type ffffffff, and then click OK.
10.Exit Registry Editor, and then restart the computer.