When you're installing new windows and doors in your home, a few simple guidelines will help you choose the right contractor and avoid the pains - or panes - of a job gone bad.

• Set a budget
  
  Work out a budget and stick to it. No matter how breathtaking your new windows or doors may be, they're not worth it if you're looking through them from the poor house.
  
  
• Know what you want
  
  Tour your local home improvement wholesaler to get a general education. At the end of your informal research, make sure you know what style doors or windows you want in your own home and what materials were used to make them.
  
  Do you want sliding glass doors or French doors? Would you like single or triple-paned glass in your windows? Perhaps tempered glass or a low-emittance feature?
  
  
• Look for specialty window & door contractors
  
  Contact contractors and installers who specialize in windows and doors. A poorly-hung door or improperly-installed window can bring down your home's value and raise your energy bills, so it's best to use a contractor who specializes in this type of work.
  
  
• Check the door & window installer's references
  
  Ask installers how long they have been in business and be sure to obtain references. Former clients can rate the installer's work, work ethic and customer service for you.
  
  
• Review a sample contract or template
  
  Make sure any contract you sign includes a specific description of the work to be done, a payment schedule, a start date and an estimated completion date.
  
  Look at samples of the installer's work. Examine them and decide whether or not you would be happy with the same quality windows or doors in your home.
  
  
• Confirm the installer's insurance
  
  A prospective window or door installer should have at least three kinds of insurance: personal liability, worker's compensation and property damage.