Editing Computer case (section)

===Internal access===
Accessing the interior components of a modern [[ATX]] tower case is done by removing the side panels. Looking front-to-back, accessing the motherboard, PSU, drive bays, and most case fan installation points are done by removing the left side panel.
Removing the right-side panel is done less often to access the space behind the motherboard mounting plate. This space is devoted to cable management, as cables routed in front of the motherboard may disrupt the flow of air within the case causing increased temperatures.<ref>{{Citation|last=Linus Tech Tips|title=Cable Management – Does it impact cooling performance? At all?...|date=2016-02-08|url=https://www.youtube.com/watch?v=YDCMMf-_ASE |archive-url=https://ghostarchive.org/varchive/youtube/20211222/YDCMMf-_ASE |archive-date=2021-12-22 |url-status=live|access-date=2018-08-11}}{{cbignore}}</ref> [[BTX (form factor)|BTX]], an uncontemporary standard, has the main side panel on the right side as opposed to the left. Some upside-down designed ATX cases are also accessed by removing the right-side panel door.

Alternatively, the case may have a single large U-shaped cover that saddles the chassis. This was ubiquitous in [[AT form factor|AT]] tower cases.

To prevent the buildup of performance-degrading dust within the case, many models feature dust filters in front of the air intake fans. While the exact method of accessing the front filters depends on the case model, it usually requires the removal of the entire front panel. Removal of the front panel itself may or may not require the removal of one or both of the side panels. If there is any doubt, consult the user's manual if possible.

Traditionally, most computer cases required [[computer case screws]] to hold components and panels in place (i.e. motherboard, PSU, drives, and expansion cards). From the early 2000s onwards there is a trend towards tool-less cases, in which components are held together with snap-in plastic rails, thumbscrews, and other methods that do not require tools; this facilitates quick assembly and modification of computer hardware and is also cheaper to manufacture.