WARNING this company issues fraudulent documents and states they are members of reputable building regulation bodies. Their supposed 10yr guarantee issued by Plastics Window Federation state they have not been members since 2002 and have been committing fraud by issuing fake guarantee certificates. I have tried to contact Prostar Windows on numerous occasions by telephone and recorded delivery letters about outstanding problems and they completely ignore the complaints. That's when I learnt they were in fact committing fraud by issuing fake documents. If you have windows, doors or conservatories installed by this company, check the paperwork very carefully and inform Trading Standards,, Plastics Window Federation and the Police if there are any irregularities. DO NOT USE this company under any circumstances. read more