There can be many reasons as to why the QuickBooks Desktop keeps freezing while opening a company file. A few of the root causes for this problem include a damaged company file or installation file, a corrupted QBWUSER.INI file. Moreover, you may have an outdated or corrupted Windows operating system, or a corrupted hard drive that might interfere with QB tasks. Additionally, having excessively long company file names or conflicts from other programs running in the background may lead to insufficient space in the hard drive.

https://proadvisorsolutions.com/blog/quickbooks-desktop-freezing-up/