To tell a genuine system window from a fake and avoid buying traps, focus on three cores - system completeness, detailed workmanship and service assurance. (1) Check system credentials to identify authenticity. Ask for the system certification and test reports: a genuine system window has a complete 'system R&D' background, and the brand should provide third-party reports for the series' thermal, water-tightness and air-tightness performance (e.g. tested to GB/T 8478-2020), not merely separate reports for the profile or glass; some high-end brands also hold EU CE or US NFRC certification, and those without are usually 'pseudo system windows'. Verify system consistency: the profile, hardware, sealing gasket and glass must belong to the same system and carry dedicated model markings (e.g. a laser-engraved system number on the profile, and a brand logo plus matching model on the hardware); if a seller mixes brands (domestic hardware on imported system profiles) or the gaskets do not match the profile, it is probably an 'assembled window'. (2) Inspect detailed workmanship to judge quality. Profile and joining: quality system-window cut faces are flat and the chamber structures well designed, with separate drainage and sound-insulation chambers; joints use 'corner glue injection' (dedicated injection holes with even, full glue lines) rather than simple screws, whereas poor windows often use corner-butting with no injection and leak or deform over time. Hardware and sealing: hardware should be a dedicated system brand (e.g. German HOPO, SIEGENIA) with smooth, non-loose handles; gaskets should be EPDM (good elasticity, slow ageing) fitting the profile groove closely with no breaks or gaps; and there should be double sealing between glass and frame (inner gasket plus outer sealant) to avoid the air leakage and fogging of single sealing. (3) Guard against marketing tricks. Be wary of cheap system windows: genuine ones usually cost over 1,000 RMB/m2 (mid-range) because of R&D and material costs, so below 800 RMB/m2 it is often a thermal-break window posing as a system window - check for downgrades such as PVC instead of nylon 66 strips and unbranded hardware. Clarify the quote scope: ask upfront whether it includes measuring, installation, glass, hardware, sealant and sill boards to avoid hidden charges for installation, hardware upgrades or sealing, and agree the glass specification (e.g. insulating Low-E, cavity thickness) and profile series to avoid goods not matching the offer. (4) Verify after-sales service for long-term use. Confirm the warranty terms: genuine brands give a written warranty covering profiles (usually 5-10 years), hardware (3-5 years) and gaskets (2-3 years) with free repair and replacement, so be cautious of oral-only promises. Examine the installation team: require a dedicated, non-outsourced system-window team, confirm a standard process (opening cleaning, waterproofing, corner glue injection, sealing) and post-installation acceptance reports (air-tightness test, water-spray test) so that good materials are not wasted by poor installation.