Encrypted image and text files can be safely previewed from within WinTrezur without leaving its environment. Other archive encrypted files types (e.g., movies) can be previewed with external software installed on your system (when your double-click them, or right-click and select the [Open] context menu), by decrypting them first to a temporary folder (with random names).
The temporary files can be deleted explicitly using [Security / Wipe / Temporary Files] menu, or they are deleted automatically when you close WinTrezur normally. If [Security / Wipe / Temporary Files] menu is not active, then there are no such temporary files.
WinTrezur file shredder tool can safely wipe such temporary files (see the tutorial section on wiping files for more details).
An alternative to wiping temporary files is to use a RAM disk folder as a temporary files folder. A RAM disk emulates a normal hard disk volume, using part of your system RAM (main memory), so the data are not really written to hard disk. When you close the computer, or disable the RAM disk, such date will be lost (forever) without leaving any traces. This feature makes a RAM disk attractive for keeping temporary sensitive files. Files can be safely removed by a RAM disk, by simply deleting them (it makes no sense to move them to Recycle Bin).
[A RAM disk tool]
There are several free third-party ram disk alternatives, such as, DataRam RamDisk (free version).
Run the ramdisk tool to create a RAM disk whose size is less than your system RAM (main memory). In Windows, you can see the amount of your system installed memory (RAM) in Control Panel / System panel. A RAM disk makes sense, when your machine has enough RAM (at least 2GB), so you can afford allocating a part of your RAM for your RAM based disk. As a rule of thumb, the RAM disk size should be enough to keep your biggest temporary (movie) file, but not bigger than half of your system RAM size.
Once you have set up a RAM disk volume, you can configure WinTrezur to use one folder on that volume as temporary files folder. Right-click on an archive encrypted file, or double-click on it if it is not an image one, to show the [Open] file window. There click the [Settings] button which is active only for archive and encrypted files.
[Open file window]
Change the temporary folder to be a newly empty RAM disk folder location. The folder does not need to exist. It will be created and removed as needed. You should not put your own files to temporary folder as they will be automatically deleted! Change the temporary folder (and click [OK] button to apply the settings). From now on, WinTrezur will use this folder to place any temporary (video) files you open explicitly with installed third-party programs.
[Change temporary folder]
When you are done viewing files with external applications, you can use [Security / Wipe / Temporary Files] tool, or simply delete the files found in the RAM disk, or close the PC so that the RAM disk contents are lost.
A RAM disk can be used also for storing small amounts of data temporary, for example, files you download from the Internet, before you append them to a WinTrezur encrypted A2R archive in persistent (normal, not RAM) hard disk storage. Do not collect too much data on the RAM disk as they could get lost if your system crashes, or loses power (or if you run out of space in the RAM disk), but append them as needed to WinTrezur A2R archives. Do not store WinTrezur A2R archives in a RAM disk volume as there is no need for that. A2R file data are fully encrypted and look like random noise.
[Creating an A2R arhvice from temporary RAM files]
Using a RAM disk leave still some data traces on your system. For example, recently accessed file names will be still collected and existing installed programs on your machine, such as, anti-virus software, can still access the data while they are in RAM disk memory. Use RAM disk only temporary before storing data in a WinTrezur encrypted A2R file and wipe system history using WinTrezur's [Security / Wipe / System History] tool.