Virtual hardware is difficult to implement even on recent dynamically reconfigurable processors when the loop body of the target application cannot be stored in the set of quickly switch-able contexts. Here, techniques for such tough cases are proposed. Differential configuration which changes only different parts of similar contexts can drastically reduce the time for re-configuration. Pairwise context assignment policy can hide the overhead of configuration with double buffering. Out-of-order context switching enables execution of available context in advance. Through an implementation example on NEC's DRP-1, it appears that the virtual hardware can be executed with practical speed by combining the proposed techniques.