repairing failed windows

Does anyone have any experience with repairing failed double glazed windows? There is a company apparently can service them by defogging and sealing the glasses. I wonder how good they are as that can save some money rather than replacing the glasses.
--
snipped-for-privacy@hotmail.com
remove 'nospam' for correct email address
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.