Opening multiple large Excel files simultaneously requires a large amount of RAM. Upgrading the RAM in the workstation should improve performance. References: CompTIA A+ Certification Exam Guide, Ninth Edition, Chapter 9

When a computer frequently freezes and requires hard restarts, the first step a technician should take, especially when hardware components have not been recently changed, is to read the event logs. Event logs can provide critical insights into what is causing the system to freeze, including errors and warnings that precede the freeze. This information is essential for diagnosing software or operating system issues that might be causing instability. Checking the temperature or updating drivers might be subsequent steps based on findings from the event logs.
References:CompTIA A+ Core 1 (220-1101) troubleshooting section, which emphasizes the importance of using system logs to diagnose issues.

The maximum distance that Cat 5, Cat 5e, Cat 6, and Cat 6a cables can be ran is 100 meters or 328 feet, according to the TIA/EIA standards. This is the maximum length for a cable segment, which is the distance between two devices, such as a switch and a computer, or a router and a printer. If the cable segment exceeds this length, the signal quality may degrade and cause errors or loss of data. Therefore, it is important to measure the cable length before installation and use repeaters or extenders if necessary.
References
1 Cable Distance | Comms InfoZone
2 Discussing Cat5 and Cat6 Max Length Limits - ShowMeCables
3 Cat5e vs Cat6 - Difference and Comparison | Diffen

The MX record is housed in the DNS (Domain Name System) which is responsible for translating domain names into IP addresses and vice versa. The MX record specifies the mail server responsible for accepting email messages on behalf of a domain name and is a resource record in the DNS123.

Enabling the audio device is the correct action to correct an audio issue where a laptop does not have any audio output from the built-in speakers and Windows Device Manager shows a down arrow for the audio device. A down arrow indicates that the audio device is disabled and needs to be enabled by right-clicking on it and selecting Enable device. Replacing the speakers, increasing the volume, or updating the driver are unlikely to solve the issue if the audio device is disabled.