HP Vectra VEi8 Supplementary Manual page 10

Replacing the Cover
Removing and Replacing the Cover and Front Panel
Before replacing the cover, ensure that all internal cables are properly
connected and safely routed.
1 If necessary, replace the front panel. To do this, insert the three
plastic tabs into the holes in the front of the PC chassis and snap the
panel in place.
2 Lower the cover and slide it into position.
3 Tighten the three thumbscrews at the rear of the PC.
4 If required, lock the cover with the key at the rear of the PC.