Ok, this is what I have done
I have virtualbox with a Windows XP pro as a virtual machine, I've installed Oracle 11g and setup a DB, and I can use Sql developer on it (the virtual os) but what Im tring to do next is use Sql developer on the host os, windows 7 Home premium, I can ping to the virtual os, but when I try to connect to the DB I get an error: The network adapter could not establisha a connection
Under :
Hostname I have put localhost and/or the IP of the virtual os
port : 1521
SID : utm (that the sid name Im using)

the listener service is running on windows xp (the virtual os)

Any help would be apreciated

you have an OS/networking mis-configuration that has NOTHING to do with Oracle.

You can validate the complete network configuration by issuing 8 ping commands

ping <own_hostname>
ping <own_IP#>
ping <other_hostname>
ping <other_IP#>

then to the same from the other system

Realize & understand that any system which is configured as "localhost",
can NOT be accessed by any remote system.

Yes, all pings worked
So now we know is not a network issue, but the last thing you typed was I can not use a localhost installation with a remote system, so my next questions would be
How can I correct this?
Do I need to reinstall Sql 11g and use the server option?

For any help, Thanks...

>How can I correct this?
at OS level change host configuration such that it has real hostname & routable IP;
something other than localhost & 127.0.0.1

Can you explain a little bit more (or a lor more), please
Would that be on the listener.ora file?
and change the localhost for the name of the virtual machine?

Thanks in advance...

Since V10 Oracle listener.ora file is NOT required.
Listener will start & run when no listener.ora file exists.
Listener will acquire needed details directly from the Operating System (OS).

These are your systems & OS, so you are free to configure as you require them to be.

No, still the same problem, and as you red on my 1st and 2nd post I can ping to the virtual machine using the ip and hostname, I can see it on my network connection and I even have notworked drives linked on both machines, so again, I dont think is a network problem
Again, under hostname I have put , 192.168.56.101, also changed to virtualxp (that's the host name/ip of my virtual machine) but still have the same error...I can see network activitie on both machines as I click on the test button but still no go...

any other suggestions....?

while logged onto the DB Server system issue following OS commands

lsnrctl status
lsnrctl service

COPY the results from above, then PASTE all back here

LSNRCTL for 32-bit Windows: Version 11.2.0.1.0 - Production on 24-FEB-2013 14:35
:36

Copyright (c) 1991, 2010, Oracle. All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC15 21)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for 32-bit Windows: Version 11.2.0.1.0 - Produ
ction
Start Date 24-FEB-2013 11:21:58
Uptime 0 days 3 hr. 13 min. 40 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File C:\app\Owner\product\11.2.0\dbhome_1\network\admin \lis
tener.ora
Listener Log File c:\app\owner\diag\tnslsnr\VirtualXP\listener\alert \log
.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\\.\ pipe\EXTPROC1521ipc)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0. 1)(PORT=1521)))
Services Summary...
Service "CLRExtProc" has 1 instance(s).
Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "utm" has 1 instance(s).
Instance "utm", status READY, has 1 handler(s) for this service...
Service "utmXDB" has 1 instance(s).
Instance "utm", status READY, has 1 handler(s) for this service...
The command completed successfully

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC15 21)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for 32-bit Windows: Version 11.2.0.1.0 - Produ
ction
Start Date 24-FEB-2013 11:21:58
Uptime 0 days 3 hr. 13 min. 40 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File C:\app\Owner\product\11.2.0\dbhome_1\network\admin \lis
tener.ora
Listener Log File c:\app\owner\diag\tnslsnr\VirtualXP\listener\alert \log
.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\\.\ pipe\EXTPROC1521ipc)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0. 1)(PORT=1521)))
Services Summary...
Service "CLRExtProc" has 1 instance(s).
Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "utm" has 1 instance(s).
Instance "utm", status READY, has 1 handler(s) for this service...
Service "utmXDB" has 1 instance(s).
Instance "utm", status READY, has 1 handler(s) for this service...
The command completed successfully

C:\Documents and Settings\Owner>lsnrctl service

LSNRCTL for 32-bit Windows: Version 11.2.0.1.0 - Production on 24-FEB-2013 14:37
:25

Copyright (c) 1991, 2010, Oracle. All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC15 21)))
Services Summary...
Service "CLRExtProc" has 1 instance(s).
Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0
LOCAL SERVER
Service "utm" has 1 instance(s).
Instance "utm", status READY, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:7 refused:0 state:ready
LOCAL SERVER
Service "utmXDB" has 1 instance(s).
Instance "utm", status READY, has 1 handler(s) for this service...
Handler(s):
"D000" established:0 refused:0 current:0 max:1022 state:ready
DISPATCHER <machine: VIRTUALXP, pid: 568>
(ADDRESS=(PROTOCOL=tcp)(HOST=VirtualXP)(PORT=1033) )
The command completed successfully

THANK YOU VERY MUCH!!!!
Here is my answer
ADDRESS=(PROTOCOL=tcp)(HOST=VirtualXP)(PORT=1033) )

I was using the correct Hostname but the wrong port...

post excerpt from c:\app\owner\diag\tnslsnr\VirtualXP\listener\alert \log.xml
which shows successful connection from Windows 7 system

</txt>
</msg>
<msg time='2013-02-24T15:47:55.176-06:00' org_id='oracle' comp_id='tnslsnr'
type='UNKNOWN' level='16' host_id='VIRTUALXP'
host_addr='192.168.56.101'>
<txt>24-FEB-2013 15:47:55 * service_update * utm * 0
</txt>
</msg>
<msg time='2013-02-24T15:48:02.174-06:00' org_id='oracle' comp_id='tnslsnr'
type='UNKNOWN' level='16' host_id='VIRTUALXP'
host_addr='192.168.56.101'>
<txt>24-FEB-2013 15:48:02 * service_update * utm * 0
</txt>
</msg>
<msg time='2013-02-24T15:48:02.933-06:00' org_id='oracle' comp_id='tnslsnr'
type='UNKNOWN' level='16' host_id='VIRTUALXP'
host_addr='192.168.56.101'>
<txt>24-FEB-2013 15:48:02 * (CONNECT_DATA=(CID=(PROGRAM=)(HOST=)(USER=Owner))( COMMAND=services)(ARGUMENTS=64)(SERVICE=LISTENER)( VERSION=186646784)) * services * 0
</txt>
</msg>
<msg time='2013-02-24T15:48:19.079-06:00' org_id='oracle' comp_id='tnslsnr'
type='UNKNOWN' level='16' host_id='VIRTUALXP'
host_addr='192.168.56.101'>
<txt>24-FEB-2013 15:48:19 * service_update * utm * 0
</txt>
</msg>
<msg time='2013-02-24T15:48:23.825-06:00' org_id='oracle' comp_id='tnslsnr'
type='UNKNOWN' level='16' host_id='VIRTUALXP'
host_addr='192.168.56.101'>
<txt>24-FEB-2013 15:48:23 * service_update * utm * 0
</txt>
</msg>
<msg time='2013-02-24T15:49:01.765-06:00' org_id='oracle' comp_id='tnslsnr'
type='UNKNOWN' level='16' host_id='VIRTUALXP'
host_addr='192.168.56.101'>
<txt>24-FEB-2013 15:49:01 * service_update * utm * 0
</txt>
</msg>
<msg time='2013-02-24T15:49:28.870-06:00' org_id='oracle' comp_id='tnslsnr'
type='UNKNOWN' level='16' host_id='VIRTUALXP'
host_addr='192.168.56.101'>
<txt>24-FEB-2013 15:49:28 * service_update * utm * 0
</txt>
</msg>
<msg time='2013-02-24T15:49:41.137-06:00' org_id='oracle' comp_id='tnslsnr'
type='UNKNOWN' level='16' host_id='VIRTUALXP'
host_addr='192.168.56.101'>
<txt>24-FEB-2013 15:49:41 * service_update * utm * 0
</txt>
</msg>
<msg time='2013-02-24T15:50:05.546-06:00' org_id='oracle' comp_id='tnslsnr'
type='UNKNOWN' level='16' host_id='VIRTUALXP'
host_addr='192.168.56.101'>
<txt>24-FEB-2013 15:50:05 * service_update * utm * 0
</txt>
</msg>
<msg time='2013-02-24T15:50:08.656-06:00' org_id='oracle' comp_id='tnslsnr'
type='UNKNOWN' level='16' host_id='VIRTUALXP'
host_addr='192.168.56.101'>
<txt>24-FEB-2013 15:50:08 * service_update * utm * 0
</txt>
</msg>
<msg time='2013-02-24T15:50:32.201-06:00' org_id='oracle' comp_id='tnslsnr'
type='UNKNOWN' level='16' host_id='VIRTUALXP'
host_addr='192.168.56.101'>
<txt>24-FEB-2013 15:50:32 * service_update * utm * 0
</txt>
</msg>
<msg time='2013-02-24T15:50:36.670-06:00' org_id='oracle' comp_id='tnslsnr'
type='UNKNOWN' level='16' host_id='VIRTUALXP'
host_addr='192.168.56.101'>
<txt>24-FEB-2013 15:50:36 * service_update * utm * 0
</txt>
</msg>
<msg time='2013-02-24T15:51:13.709-06:00' org_id='oracle' comp_id='tnslsnr'
type='UNKNOWN' level='16' host_id='VIRTUALXP'
host_addr='192.168.56.101'>
<txt>24-FEB-2013 15:51:13 * (CONNECT_DATA=(CID=(PROGRAM=)(HOST=__jdbc__)(USER= SYSTEM))(SERVICE_NAME=demoutm)) * (ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0.1)(PORT=1059) ) * establish * demoutm * 12514
</txt>
</msg>
<msg time='2013-02-24T15:51:13.709-06:00' org_id='oracle' comp_id='tnslsnr'
type='UNKNOWN' level='16' host_id='VIRTUALXP'
host_addr='192.168.56.101'>
<txt>TNS-12514: TNS:listener does not currently know of service requested in connect descriptor
</txt>
</msg>

But know I have this problem (well I can live with it), every time I turn on my vitual XP machine, the port changes...