I have a Catalyst 3750V2-48PS running IOS c3750-ipservicesk9-mz.122-53.SE2.bin and everything is working fine.

Now I need to downgrade the IOS to c3750-ipservicesk9-mz.122-50.SE4.bin so I did the following:

cat3750-v2#sh flash:

Directory of flash:/

    2  -rwx    12700373   Mar 1 1993 02:47:41 +00:00  c3750-ipservicesk9-mz.122-53.SE2.bin
    3  -rwx       13155  Aug 31 2010 01:14:42 +00:00  config.text
    4  -rwx         684   Mar 1 1993 00:15:44 +00:00  vlan.dat
    5  -rwx    12241182  Aug 31 2010 01:16:41 +00:00  c3750-ipservicesk9-mz.122-50.SE4.bin
    7  -rwx          24  Aug 31 2010 01:14:43 +00:00  private-config.text
    6  -rwx        3096  Aug 31 2010 01:14:43 +00:00  multiple-fs

27998208 bytes total (2832896 bytes free)
cat3750-v2#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
cat3750-v2(config)#boot system flash:c3750-ipservicesk9-mz.122-50.SE4.bin
cat3750-v2(config)#end
cat3750-v2#wr mem
Building configuration...
[OK]
cat3750-v2#sh run | i boot
cat3750-v2#

As you can see, when I type "show run | i boot" nothing show up meaning that if I reboot the switch,

it will come back up with c3750-ipservicesk9-mz.122-53.SE2.bin.

Anyone know how to goes about downgrading the switch from c3750-ipservicesk9-mz.122-53.SE2.bin to

c3750-ipservicesk9-mz.122-50.SE4.bin SAFELY without removing the IOS image c3750-ipservicesk9-mz.122-53.SE2.bin from the flash?

thanks in advance.