Computer enclosure having expansion card retention frame

A computer enclosure, comprising:

• a shell body comprising a main chassis, and a side wall perpendicularly extending from an edge of the main chassis, the main chassis configured for fixing a main circuit board thereto, the side wall defining an elongated through hole extending along a first direction perpendicular to the main chassis;
• and
• an expansion card retention assembly for fixing a first expansion card and a second expansion card, the second expansion card comprising an expansion card bracket, the expansion card retention assembly comprising:
• a first expansion frame fixed on the side wall and adjacent to the through hole, the first expansion frame comprising a main board with a length in the first direction less than that of the through hole, the first expansion frame being configured for fixing the first expansion card, and
• a second expansion frame fixed on the side wall, the second expansion frame comprising an elongated main plate extending along the first direction, a first support platform perpendicularly extending from an end of the main plate, and a mounting tab perpendicularly extending from an opposite end of the first support platform to the main plate, the mounting tab being fixed on the side wall, the main plate and the first support platform being configured for matingly engaging with the expansion card bracket of the second expansion card.