Dear All,

I've read this information Bellow :

PIX Security Appliance versions 7.0 and later use a different Flash file format than earlier PIX versions. Therefore, you cannot downgrade from a 7.0 image to a 6.x image with the use of the copy tftp flash command. Instead, you must use the downgrade command. Failure to do so causes the PIX to get stuck in a boot loop.

Refer to the Downgrade from PIX 7.x to 6.x section of Cisco Secure PIX Security Appliance 7.0 and ASDM Software Upgrade Procedure if the PIX had been successfully upgraded to PIX 7.0.

If the upgrade procedure is unsuccessful or there is a faulty upgrade, the PIX might get stuck in a boot loop. Complete these steps to recover from a faulty upgrade:

1. Set the PIX to monitor mode.

2. Load the erasedisk6xx.bin file via TFTP. The erasedisk6xx.bin file erases your Flash file system.

Note: You need to get this file from Cisco Technical Support and this step should be performed carefully.

3. When the system re-starts, set the PIX to monitor mode again.

4. Load the new 6.x version file in the PIX via TFTP.

For thats information, would you tell me Link for download : erasedisk6xx.bin