For Dell Inspiron 1545, you may have DELL DataSafe Local back UP option. Please refer the link to Backup the Factory OEM Image. Dell - Support
You will need 2 DVD's for this. You may get Split error when you try to Burn them. Please keep trying twice or thrice and you can succeed. This Split error is a reported one. But, if you try once or twice, you should be able to do it. I just have backed up the same Yesterday.