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Every format, every TV, every fix.

Whatever file you've got and whatever screen you want it on, there's a short answer here. Straight to the fix, in words that make sense.

43 articles 6 topics Updated with every release

Most trouble with video on a Windows PC comes down to three things: a file the machine cannot open, a subtitle that will not behave, or a television that refuses what you send it. The guides below cover all three, written for people who want the problem gone rather than an explanation of codecs.

If you are troubleshooting something specific, the categories jump straight to it. If you are setting up for the first time, casting to your TV and playing your files are the two worth reading.

Formats & codecs 10 Casting videos to your TV 12 Subtitles 6 Picture & HDR 6 Sound 4 Library & everyday use 5

Cast video to Chromecast from PC — any format, full 4K HDR

Every format and codec, sent to the television in full 4K HDR with your subtitles on the picture — and your PC still in charge of playback.

AIX Player's cast device list finding TVs on the network

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Formats & codecs

The files people are told they cannot open — and why that stops being true.

MKV won’t play on Windows 11? How to fix it Why the file refuses, and how to open any MKV with every track intact. How to play HEVC / H.265 on Windows 11 Why many PCs cannot decode H.265, and how to get the picture back. AV1 playback on Windows, explained The newest codec, what needs it, and how to play it smoothly today. MP4 vs MKV — which should you keep? What each container actually holds, and when the difference matters. Playing TS and M2TS Blu-ray files Disc rips open directly, chapters and surround audio included. AVI file not playing on Windows 11? Old files from old drives, opening properly again. WebM, VP9 and VP8 files Web-native video on the desktop, without a browser. MOV file won’t open on Windows? Phone and camera footage, opened natively. What 10-bit video means for what you see Banding, colour depth, and why the number matters. "Unsupported codec" — fixed for good The one change that ends the error for every file.

Casting videos to your TV

Getting the file on your PC onto the big screen, in full quality, subtitles included.

Cast video to Chromecast from PC Every format, in full 4K HDR, with subtitles on the picture. Cast video to Google TV from PC Cast built into the set — nothing to plug in. Cast video to Android TV from PC Sets and boxes with Cast as standard. Cast video to Fire TV from Windows PC Fire TV Stick, Fire TV Cube and built-in Fire TV sets. Cast video to Roku from PC MKV, MP4 and the rest — no converting, found automatically. Cast video to Apple TV from Windows PC Reach an Apple TV box from Windows, in full quality. Cast video to LG Smart TV from PC Connects straight to the television — no dongle needed. Cast video to Samsung Smart TV from PC Connects straight to the set, with subtitles intact. Cast video to Sony Bravia TV from PC Connects straight to Bravia sets, in full quality. Cast video to NVIDIA Shield from PC The most capable box — often no conversion at all. Cast video from PC to a DLNA-enabled Smart TV Reaches older televisions with no Chromecast built in. Why subtitles vanish when you cast — and how to keep them The single most common casting complaint, solved.

Subtitles

Loading them, timing them, styling them, and getting them onto the TV.

How to add an external SRT subtitle file Load any subtitle file without renaming it to match the video. Fix subtitles that are out of sync Shift the timing while the film plays, once per file. Make subtitles easier to read Size, colour, outline and backing box for any room. Two subtitle tracks at once for language learning Native and target language on screen together. SRT, ASS, VTT and PGS explained Which subtitle format does what, and which to choose. Subtitles not showing on your MKV? What to check The handful of causes, in order of likelihood.

Picture & HDR

Getting the image the film was graded for, without stutter or washed-out colour.

How to play 4K HDR video on a Windows PC What HDR adds, and how to get it looking right on your screen. Why HDR looks washed out on a PC The Windows setting behind grey, flat HDR — and the fix. 4K video lagging or stuttering on your PC? Move the work to your graphics card and the frame drops stop. Hardware acceleration: Intel, NVIDIA and AMD What each does, and why the fans stay quiet. Native playback on Snapdragon and Copilot+ PCs Arm64 builds, no emulation, no battery penalty. Picture adjustment worth making Brightness, contrast and aspect, without ruining the grade.

Sound

The mix problems people notice most, and the controls that solve them.

How to make movie dialogue louder on a PC Why modern mixes bury speech, and how to lift it. Surround and lossless audio on a PC Keep the multi-channel mix instead of folding it to stereo. Fix audio that is out of sync with the picture Nudge the delay until lips and words agree. Using the 10-band equaliser well Presets that suit films, and what to change by hand.

Library & everyday use

Living with a collection: finding things, resuming them, watching while you work.

Keep a large video library organised Folders, playlists, favourites and search that keeps up. Watch video in picture-in-picture on Windows The floating window and the mini player, side by side. Resume, bookmarks and chapters Pick up mid-film weeks later, and mark what matters. Build playlists that play straight through Queue an evening, in the order you want it. Keyboard shortcuts worth learning The dozen keys that make playback feel instant.

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