Please make sure that you have enough space on your drive. You need at least 10% free space at all times (we recommend 20% for Note Caddy processing) and an additional 2x the size of the database.

Clear the c:\temp and c:\users\username\appdata\local\temp folders. You will need to show system and hidden files. See this tutorial for showing system and hidden files:
Hold'Em Manager 2 FAQs - Poker Software :: How are Hidden Files Viewed in Windows?

Please see this FAQ to alleviate any security bottlenecks - Hold'Em Manager 2 FAQs - Poker Software :: Set Correct Permissions on files and folders HM2 use