Dealing with a similar issue, I found the following solution effective:

Upgrade NPM

npm install npm@latest -g

Update typescript

npm -g upgrade typescript

or

npm install typescript@latest -g

You can now verify the update by running:

tsc --version

Version 2.1.5

Since the correct answer I selected didn't solve my problem, I thought I'd share how I managed to fix it.

I had to eliminate

C:\Program Files (x86)\Microsoft SDKs\TypeScript\1.0\

from my PATH environment variable.

After doing that, I was able to execute this command and verify that I had the expected version:

C:\>tsc --version
message TS6029: Version 1.5.3

If you're facing difficulties with this, give running the command WHERE tsc a shot in either Command Prompt or Node.js Command Prompt. This should provide you with all the locations where it is installed. Simply eliminate any unnecessary locations from the PATH environment variable.

Despite upgrading to the latest version of TypeScript, I still encountered an issue where the version displayed was 1.0.3 when using tsc -v.

Although the suggested solution didn't work for me initially, I decided to follow @BenR's advice by removing the PATH C:\Program Files (x86)\Microsoft SDKs\TypeScript\1.0\ from my System Variables.

https://i.sstatic.net/fJNOT.png

I then opened a new Windows command prompt and entered the following command:

tsc -v
Version 2.3.3

After taking these steps, I successfully compiled my TypeScript files using tsc file.ts.

I hope this solution proves helpful to others facing similar issues.

To begin, open a command line tool such as cmd.exe or Git Bash, then run the following command:

 npm install -g typescript@latest

This command serves to:

Verify whether Typescript is currently installed and ..

1. If it is already installed, update it to the latest version
2. If it is not yet installed, install the most recent version

Note that some users have experienced issues with the following command if Typescript is already on your system:

npm update -g typescript@latest

---

You can test the version by using the following command:

tsc -v  // this will display the version of Typescript installed on your local machine

https://i.sstatic.net/Wp8A6.png

Additionally, you can check for the latest available version of Typescript in the npm registry by running:

npm view typescript version  // this will show the latest version available in the npm registry

Dealing with a similar issue on my Linux system, it seemed to be linked to the node version manager that I was using.

To resolve the issue, I located the tsc files and manually removed the corresponding folders:

$ which tsc
/home/user/.nvm/versions/node/v12.18.2/bin/tsc

$ cd /home/user/.nvm/versions/node/v12.18.2/bin/
$ ll
...
lrwxrwxrwx 1 user user       38 Jul 11 09:45 tsc -> ../lib/node_modules/typescript/bin/tsc*
lrwxrwxrwx 1 user user       43 Jul 11 09:45 tsserver -> ../lib/node_modules/typescript/bin/tsserver*
...

$ rm -rf ../lib/node_modules/typescript/ tsc tsserver

Encountered a similar issue on a Windows 8 machine with restricted admin access, making it impossible to uninstall global typescript or modify the system's PATH.

Here is how to work around this situation when trying to launch typescript projects:

1. Install a local version of typescript for your project using the command: npm install typescript@latest (do not include the -g flag)

2. Add build scripts to your package.json file as follows:

   scripts: {
       "clean": "rimraf coverage build tmp",
       "build": "tsc -p tsconfig.release.json",
       "build:watch": "tsc -w -p tsconfig.release.json",
       "lint": "tslint -t stylish --project \"tsconfig.json\"",
       "test": "jest --coverage",
       "test:watch": "jest --watch"
   }

3. Run the typescript compiler using the local version installed for your project by running: npm run build:watch. This will execute tsc -w -p tsconfig.release.json using the project's local tsc from the node_modules directory.

1. On my Windows OS computer, I encountered a problem with TypeScript due to Visual Studio installing its own version into the System Path
2. To resolve this, I uninstalled 'TypeScript for Visual Studio' from Programs and Features (or 'Add or remove programs')
3. Next, I installed the latest version of TypeScript using the command prompt: 'npm install -g typescript@latest'
4. This fixed the issue for me!

Although this is an older question, I wanted to share my solution since none of the existing answers addressed my specific problem. Hopefully it helps others facing the same issue.

UPDATE 9/26/2022

After executing npm install typescript@latest -g command, I encountered the following errors:

npm ERR! code EEXIST
npm ERR! path C:\Users\chrisds\AppData\Roaming\npm\tsc
npm ERR! EEXIST: The file already exists
npm ERR! File exists: C:\Users\chrisds\AppData\Roaming\npm\tsc
npm ERR! Remove the existing file and try again, or run npm
npm ERR! with --force to overwrite files recklessly.

npm ERR! A detailed log of this operation can be found in:
npm ERR!     C:\Users\chrisds\AppData\Local\npm-cache\_logs\2022-09-26T20_55_57_959Z-debug-0.log

As a solution, I located the path and removed all occurrences of tsc such as: tsc, tsc.cmd, tsc.psl, tsserver, tsserver.cmd, tsserver.psl

Then, I re-executed the command npm install typescript@latest -g and it worked successfully.

C:\Users\chrisds\Documents\typescript-angular>tsc -v

Version 4.8.3

I faced a similar issue and found that none of the common solutions worked for me. I am using Windows 10 with Visual Studio 2017.

To troubleshoot, I used where tsc from the command prompt to locate the path where tsc was being resolved. I discovered that it pointed to a location like:

C:\Program Files (x86)\Microsoft SDKs\TypeScript\x.xx

. However, this path was not present in my System or User PATH variables.

Fortunately, I came across a helpful comment on GitHub which guided me towards the solution. I use Console2 and my default console tab launches a Visual Studio-enhanced console through a specific .bat file located at:

C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\Common7\Tools\VsDevCmd.bat

Although this particular .bat file did not reference TypeScript specifically, it executed all other .bat files within

C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\Common7\Tools\vsdevcmd\ext

. Among these, one file named typescript.bat caught my attention. To resolve the issue, I simply renamed that file to a different extension, restarted the console, and the problem was resolved.

I cannot guarantee that this workaround will not have any negative effects on Visual Studio, especially if TypeScript is used within the environment. There's a possibility that a future update to Visual Studio may restore the file. But, for now, this solution works perfectly for me.

Switching from using npm to utilizing npx resolved the issue for me.