diff --git a/api/src/com/cloud/api/commands/SetVMOSTypeCmd.java b/api/src/com/cloud/api/commands/SetVMOSTypeCmd.java
new file mode 100644
index 00000000000..bb1971e9fc9
--- /dev/null
+++ b/api/src/com/cloud/api/commands/SetVMOSTypeCmd.java
@@ -0,0 +1,89 @@
+/**
+ *  Copyright (C) 2010 Cloud.com, Inc.  All rights reserved.
+ * 
+ * This software is licensed under the GNU General Public License v3 or later.
+ * 
+ * It is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+package com.cloud.api.commands;
+
+import org.apache.log4j.Logger;
+
+import com.cloud.api.ApiConstants;
+import com.cloud.api.BaseAsyncCmd;
+import com.cloud.api.BaseCmd;
+import com.cloud.api.Implementation;
+import com.cloud.api.Parameter;
+import com.cloud.api.ServerApiException;
+import com.cloud.api.response.UserVmResponse;
+import com.cloud.event.EventTypes;
+import com.cloud.template.VirtualMachineTemplate;
+import com.cloud.user.Account;
+import com.cloud.uservm.UserVm;
+
+@Implementation(description="Set VM OS Type.", responseObject=UserVmResponse.class)
+public class SetVMOSTypeCmd extends BaseCmd {
+    public static final Logger s_logger = Logger.getLogger(SetVMOSTypeCmd.class.getName());
+
+    private static final String s_name = "SetVMOSTypeResponse";
+
+    /////////////////////////////////////////////////////
+    //////////////// API parameters /////////////////////
+    /////////////////////////////////////////////////////
+
+    @Parameter(name=ApiConstants.VIRTUAL_MACHINE_ID, type=CommandType.LONG, required=true, description="the ID of the virtual machine")
+    private Long virtualMachineId;
+
+    @Parameter(name=ApiConstants.OS_TYPE_ID, type=CommandType.LONG, required=true, description="the ID of the OS Type that best represents the OS of this template.")
+    private Long osTypeId;
+
+    /////////////////////////////////////////////////////
+    /////////////////// Accessors ///////////////////////
+    /////////////////////////////////////////////////////
+
+    public Long getOsTypeId() {
+        return osTypeId;
+    }
+
+    public Long getVirtualMachineId() {
+        return virtualMachineId;
+    }
+
+
+    /////////////////////////////////////////////////////
+    /////////////// API Implementation///////////////////
+    /////////////////////////////////////////////////////
+
+    @Override
+    public String getName() {
+        return s_name;
+    }   
+
+   
+    @Override
+    public void execute(){
+        boolean result = _userVmService.setVMOSType(this);
+        if (result) {
+            UserVm userVm = _responseGenerator.findUserVmById(virtualMachineId);
+            if (userVm != null) {
+                UserVmResponse response = _responseGenerator.createUserVmResponse(userVm);            
+                response.setResponseName(DeployVMCmd.getResultObjectName());           
+                this.setResponseObject(response);
+            } else {
+                throw new ServerApiException(BaseCmd.INTERNAL_ERROR, "Failed to set VM OS type");
+            }
+        } else {
+            throw new ServerApiException(BaseCmd.INTERNAL_ERROR, "Failed to set VM OS type");
+        }
+    }
+}
diff --git a/api/src/com/cloud/vm/UserVmService.java b/api/src/com/cloud/vm/UserVmService.java
index bc73f6a4d3f..836d784e45e 100755
--- a/api/src/com/cloud/vm/UserVmService.java
+++ b/api/src/com/cloud/vm/UserVmService.java
@@ -28,6 +28,7 @@ import com.cloud.api.commands.DetachVolumeCmd;
 import com.cloud.api.commands.RebootVMCmd;
 import com.cloud.api.commands.RecoverVMCmd;
 import com.cloud.api.commands.ResetVMPasswordCmd;
+import com.cloud.api.commands.SetVMOSTypeCmd;
 import com.cloud.api.commands.StartVMCmd;
 import com.cloud.api.commands.StopVMCmd;
 import com.cloud.api.commands.UpdateVMCmd;
@@ -63,6 +64,13 @@ public interface UserVmService {
      */
     UserVm destroyVm(long vmId) throws ResourceUnavailableException, ConcurrentOperationException;
     
+    /**
+     * Destroys one virtual machine
+     * @param VMId the id of virtual machine
+     * @param OSTypeId the id of guest OS type
+     */
+    boolean setVMOSType(SetVMOSTypeCmd cmd);
+    
     /**
      * Resets the password of a virtual machine.
      * @param cmd - the command specifying vmId, password
diff --git a/client/tomcatconf/commands.properties.in b/client/tomcatconf/commands.properties.in
index 9ba071ca1ef..a8f1371a9db 100755
--- a/client/tomcatconf/commands.properties.in
+++ b/client/tomcatconf/commands.properties.in
@@ -34,6 +34,7 @@ listResourceLimits=com.cloud.api.commands.ListResourceLimitsCmd;15
 
 #### VM commands
 deployVirtualMachine=com.cloud.api.commands.DeployVMCmd;11
+setVMOSType=com.cloud.api.commands.SetVMOSTypeCmd;15
 destroyVirtualMachine=com.cloud.api.commands.DestroyVMCmd;15
 rebootVirtualMachine=com.cloud.api.commands.RebootVMCmd;15
 startVirtualMachine=com.cloud.api.commands.StartVMCmd;15
@@ -239,4 +240,4 @@ listNetworkOfferings=com.cloud.api.commands.ListNetworkOfferingsCmd;15
 #### network commands
 createNetwork=com.cloud.api.commands.CreateNetworkCmd;15
 deleteNetwork=com.cloud.api.commands.DeleteNetworkCmd;15
-listNetworks=com.cloud.api.commands.ListNetworksCmd;15
\ No newline at end of file
+listNetworks=com.cloud.api.commands.ListNetworksCmd;15
diff --git a/server/src/com/cloud/vm/UserVmManagerImpl.java b/server/src/com/cloud/vm/UserVmManagerImpl.java
index 2f7d5525991..665ae2fe234 100755
--- a/server/src/com/cloud/vm/UserVmManagerImpl.java
+++ b/server/src/com/cloud/vm/UserVmManagerImpl.java
@@ -75,6 +75,7 @@ import com.cloud.api.commands.DetachVolumeCmd;
 import com.cloud.api.commands.RebootVMCmd;
 import com.cloud.api.commands.RecoverVMCmd;
 import com.cloud.api.commands.ResetVMPasswordCmd;
+import com.cloud.api.commands.SetVMOSTypeCmd;
 import com.cloud.api.commands.StartVMCmd;
 import com.cloud.api.commands.StopVMCmd;
 import com.cloud.api.commands.UpdateVMCmd;
@@ -3270,6 +3271,18 @@ public class UserVmManagerImpl implements UserVmManager, UserVmService, VirtualM
         }
         return _vmDao.findById(id);
 	}
+	
+    @Override
+    public boolean setVMOSType(SetVMOSTypeCmd cmd) {
+        long id = cmd.getVirtualMachineId();
+        UserVmVO vmInstance = _vmDao.findById(id);
+        if (vmInstance == null) {
+            throw new CloudRuntimeException("Unable to find virtual machine with id " + id + ", internal error.");
+        }
+        vmInstance.setGuestOSId(cmd.getOsTypeId());
+        _vmDao.update(id, vmInstance);
+        return true;
+    }
 
 	@Override
 	public UserVm startVirtualMachine(StartVMCmd cmd) throws ExecutionException, ConcurrentOperationException, ResourceUnavailableException, InsufficientCapacityException {