This paper broadly describes two computational fluid dynamics (CFD) analysis methods to predict the de-icing phenomenon over the vehicle windshield and front side windows. 1 Solid Modeling Method: In this method, the windshield and window glasses are modeled as solid and 2 Shell Modeling Method: Here, windshield and side window glasses are modeled as shell elements and considered as wall with defined thickness as input condition to capture the correct heat transfer effect due to the conduction and convection from warm air to ice layer. The CFD analyses by both methods are done in two key-steps: a) First, steady state velocity distributions for several different defroster flow rates are calculated; b) Secondly, based on the pre calculated velocity fields, the defogging time is estimated. The solidification and melting model is used to simulate the ice melting process over the glasses available with commercial CFD software Fluent. The defroster design requirement and design parameters are also explained. Through CFD analyses it is observed that predicted defrost pattern by both methods are similar and hence by using Shell Modeling Method for de-icing analysis, the computational time can be reduced drastically. The comparison between wind tunnel test and CFD result for windshield and front side windows show that the CFD approach can be a very useful design tool for the design of the vehicle defroster system and vehicle development cycle time and cost can be reduced significantly.