To remove a column from newform.aspx if you dont want the user to enter the values for it explicitly then follow the steps in the list for which u need to customize the form.
- Go to Settings -> List Settings -> Advanced Settings
- Change Allow management of content types to yes
- Now in settings you will get a heading Content Types. Clicking on this displays all the columns that are in that list.
- Click on which you want to change the properties.
- In columns settings choose the appropriate option.(In this case hidden).
Click OK and if you view the Newform.aspx the column will be hidden.