Many programs need access to a temp directory.

In Windows, a temp directory exists at many places, e.g.

• C:\temp
• C:\tmp
• C:\Windows\Temp

^{assuming C: is your Windows drive.}
However, it's mostly this location that programs - especially installers - try to access: C:\Users\<username>\AppData\Local\Temp.

This can as well be confirmed by firing echo %TEMP% on command line.
If this location is or becomes inaccessible to programs, you may see this generic error:

INTERNAL ERROR - Can't create temporary directory

If this happens, we can fix it in two ways:

• by fixing the permissions on this folder
• by having another path for the %TMP% variable

Fix Permissions

1. Go to the parent folder in Windows explorer C:\Users\<username>\AppData\Local\.
2. Right click on Temp, and go to the Security tab.
3. Once we are here, we need to see if Authenticated Users have access and if yes, what are the permissions. If this entry is not there, click on Edit and add it and then ensure the following permissions are there:

Click Ok or Apply and we are good.

Change %TEMP% Variable

Try this only if the suggestion given above is not possible to implement or doesn't work.
For this, simply type Environ... in Start Menu and select Edit the system environment variables.

In the meantime, create any other folder anywhere, e.g. C:\NewTemp.

There in the User variables, change the value of TEMP, or if needed, of TMP as well, and make them point to this newly created path.