eLightbulbs.com typically has a return policy that may specify the conditions under which returns are accepted. Generally, it is important to review the specific terms outlined on the website to determine if installed light bulbs can be returned. Typically, most retailers prefer that items be returned in their original condition and packaging. Once bulbs have been installed, they may not be eligible for return due to hygienic or safety reasons. However, if the light bulbs are defective or if there has been an error in the order, it is possible that exceptions can be made. It is advisable to check the return policy section on eLightbulbs.com for detailed information regarding installed products. Policies may vary based on manufacturer warranties or other factors, so being informed will help clarify what options are available. For any specific questions, it is best to consult the website directly for further details on returns and exchanges.