Backup Assembly from GAC

Collect Assembly files from Global Assembly Cache
Using below command you can copy Assembly file to your local path.

1. Open Command Prompt
2. type this command "copy C:\Windows\assembly\GAC_MSIL\DLLName\1.0.0.0__PublicKeyToken\DLLNAME.dll c:\OldDlls_Backup\"

See Example : copy C:\Windows\assembly\GAC_MSIL\MyAssemblyFile\1.0.0.0__9f4da00116c38999\MyAssemblyFile.dll c:\OldDlls_Backup\

Then see the "c:\OldDlls_Backup\" folder, one file will be copy from GAC.
Happy Coding !!!

Backup and Restore using stsadm.exe

You can backup & restore using below ways.

1. Using STSADM.exe command.
2. From Central Administrator Backup & Restore.

Backup - Restore using STSADM command
Open Start > Run > type "cmd" OR "command"
then type "cd C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\BIN"
Then you can use command as per your requirement.
Backup Site Collection
stsadm -o backup -url http://webapplication/SiteCollection/" -filename "C:\backupFolder"
Restore Site Collection
stsadm -o restore -url http://webapplication/SiteCollection/" -filename "C:\backupFolder"
Backup Farm
stsadm -o backup -directory "C:\FarmBackupFolder\" -backupmethod Full
Restore Farm
If you want to overwrite existing farm use stsadm -o restore -directory "C:\FarmBackupFolder\" -restoremethod overwrite
If you want to restore new farm use
stsadm -o restore -directory "C:\FarmBackupFolder\" -restoremethod new