if you type in "get the fog out" in your search engine you will find a company called ableglaze in blackpool who can repair your units without replacing them,I dont know how much they charge but there is no diy way of repairing them,you would have to replace with new.hope this helps
shaun www.sdwupvcrepair.co.uk
September 2008
Afraid not .They might be covered under a guarantee but there is no choice about replacing them.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix windows and doors.