Steam is validating game files
Some old games may also have graphical issues with Steam’s in-game overlay – the screen that appears when you press Shift Tab while in a game.
You can disable the overlay for an individual game by right-clicking the game in your Steam library, selecting Properties, and unchecking the Enable Steam Community In-Game check box.
To confirm this, I installed Skyrim Performance Monitor (available on Nexus) and launched my Skyrim game from the program.
Unfortunately, I'm using an ENB, so an in-game counter was not available.
Steam periodically detects the closest download server to you.
However, these download servers can become overloaded – if games are downloading slowly, you may want to change your download server.
In other words, there were fewer delays between switching.
The CTDs I have had lately is not a memory block issue, but rather perhaps reaching the 3.1GB crash limit.
From the Settings window, click the Downloads Cloud tab and select a different server from the Download region box.Also, if you've edited your files, it's a good idea to make a copy of those elsewhere as they will also get overwritten.If you experience any issues while launching the game, please disable all non-essential programs, including any anti-virus software on your computer to avoid corrupted files.To fix corrupted game files, you can have Steam validate the game’s cache on your system.Steam will examine the game’s files and – if any problems are detected – will re-download the corrupted files from Steam’s servers.