Please post the first 50 or so lines of your log.

Cheers

09/03/2025 10:56:34 | | cc_config.xml not found - using defaults
09/03/2025 10:56:34 | | Starting BOINC client version 8.0.2 for windows_x86_64
09/03/2025 10:56:34 | | log flags: file_xfer, sched_ops, task
09/03/2025 10:56:34 | | Libraries: libcurl/8.7.0-DEV Schannel zlib/1.3.1
09/03/2025 10:56:34 | | Data directory: C:\ProgramData\BOINC
09/03/2025 10:56:34 | | Running under account Rosa
09/03/2025 10:56:34 | | CUDA: NVIDIA GPU 0: GeForce GT 740 (driver version 456.71, CUDA version 11.1, compute capability 3.0, 1024MB, 1024MB available, 100 GFLOPS peak)
09/03/2025 10:56:34 | | OpenCL: NVIDIA GPU 0: GeForce GT 740 (driver version 456.71, device version OpenCL 1.2 CUDA, 1024MB, 1024MB available, 100 GFLOPS peak)
09/03/2025 10:56:34 | | Windows processor group 0: 16 processors
09/03/2025 10:56:34 | | Host name: Rosa-PC
09/03/2025 10:56:34 | | Processor: 16 GenuineIntel 11th Gen Intel(R) Core(TM) i7-11700F @ 2.50GHz [Family 6 Model 167 Stepping 1]
09/03/2025 10:56:34 | | Processor features: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss htt tm pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movebe popcnt aes f16c rdrandsyscall nx lm avx avx2 avx512f avx512dq adx avx512ifma avx512cd avx512bw avx512vl avx512vbmi avx512_vbmi2 gfni vaes vpclmulqdq avx512_vnni avx512_bitalg avx512_vpopcntdq vmx tm2 pbe fsgsbase bmi1 smep bmi2
09/03/2025 10:56:34 | | OS: Microsoft Windows 10: Professional x64 Edition, (10.00.19045.00)
09/03/2025 10:56:34 | | Memory: 7.90 GB physical, 15.90 GB virtual
09/03/2025 10:56:34 | | Disk: 232.37 GB total, 65.04 GB free
09/03/2025 10:56:34 | | Local time is UTC +1 hours
09/03/2025 10:56:34 | | No WSL found.
09/03/2025 10:56:39 | World Community Grid | General prefs: from World Community Grid (last modified 03-Mar-2025 14:27:56)
09/03/2025 10:56:39 | World Community Grid | Host location: none
09/03/2025 10:56:39 | World Community Grid | General prefs: using your defaults
09/03/2025 10:56:39 | | Preferences:
09/03/2025 10:56:39 | | - When computer is in use
09/03/2025 10:56:39 | | - 'In use' means mouse/keyboard input in last 3.00 minutes
09/03/2025 10:56:39 | | - don't use GPU
09/03/2025 10:56:39 | | - max CPUs used: 16
09/03/2025 10:56:39 | | - Use at most 60% of the CPU time
09/03/2025 10:56:39 | | - suspend if non-BOINC CPU load exceeds 50%
09/03/2025 10:56:39 | | - max memory usage: 3.95 GB
09/03/2025 10:56:39 | | - When computer is not in use
09/03/2025 10:56:39 | | - max CPUs used: 16
09/03/2025 10:56:39 | | - Use at most 60% of the CPU time
09/03/2025 10:56:39 | | - suspend if non-BOINC CPU load exceeds 50%
09/03/2025 10:56:39 | | - max memory usage: 5.92 GB
09/03/2025 10:56:39 | | - Suspend if running on batteries
09/03/2025 10:56:39 | | - Leave apps in memory if not running
09/03/2025 10:56:39 | | - Store at least 0.20 days of work
09/03/2025 10:56:39 | | - Store up to an additional 0.30 days of work
09/03/2025 10:56:39 | | - max disk usage: 10.00 GB
09/03/2025 10:56:39 | | - (to change preferences, visit a project web site or select Preferences in the Manager)
09/03/2025 10:56:39 | | Setting up project and slot directories
09/03/2025 10:56:39 | | Checking active tasks
09/03/2025 10:56:39 | World Community Grid | URL http://www.worldcommunitygrid.org/; Computer ID 8863904; resource share 100
09/03/2025 10:56:39 | World Community Grid | Not using NVIDIA GPU: project preferences
09/03/2025 10:56:39 | | Setting up GUI RPC socket
09/03/2025 10:56:39 | | Checking presence of 124 project files
09/03/2025 10:56:39 | | Suspending GPU computation - computer is in use
09/03/2025 10:56:39 | World Community Grid | Sending scheduler request: To fetch work.
09/03/2025 10:56:39 | World Community Grid | Requesting new tasks for CPU
09/03/2025 10:56:40 | World Community Grid | Scheduler request completed: got 0 new tasks
09/03/2025 10:56:40 | World Community Grid | No tasks sent
09/03/2025 10:56:40 | World Community Grid | No tasks are available for Africa Rainfall Project
09/03/2025 10:56:40 | World Community Grid | No tasks are available for OpenPandemics - COVID 19
09/03/2025 10:56:40 | World Community Grid | No tasks are available for OpenPandemics - COVID-19 - GPU
09/03/2025 10:56:40 | World Community Grid | Tasks are committed to other platforms
09/03/2025 10:56:40 | World Community Grid | Tasks for NVIDIA GPU are available, but your preferences are set to not accept them
09/03/2025 10:56:40 | World Community Grid | Tasks for AMD/ATI GPU are available, but your preferences are set to not accept them
09/03/2025 10:56:40 | World Community Grid | Tasks for Intel GPU are available, but your preferences are set to not accept them
09/03/2025 10:56:40 | World Community Grid | Project requested delay of 121 seconds

My first thought would be memory exhaustion with 16 processors and only 8GB of memory. Subtract out the OS and any apps and it leaves less than 500MB per MCM task. I would set boinc to run only 8 or fewer tasks to see if the situation improves. Just a quick thoought

I agree that 3.95 GB in the preferences is going to be too small for for a 16 processor load, especially if they are running African rainfall Project. That number needs to raised in the preferences or the number of work units need to be restricted.

Cheers

MCM is using currently around 39MB per task on my computer, I've seen there higher values in the past, but nothing even close to the 250MB, which are available per task on RoseLay's computer. But of course this is not a computer which can run ARP, that should be disabled. Run only MCM, than all cores can be used.

Anyway, this is nothing, that should cause computer crashes like that. If there's not enough memory available, either BOINC will simply not start 16 tasks at once or in worst case some of the tasks might error out, but the computer shouldn't crash. I mean, just open the task manager and watch the memory usage until the computer crashes, I strongly doubt this is the issue.

This sounds more like an unstable system, either because of overheating, unstable overclocking and/or undervolting, wrong BIOS settings, driver issues or simply hardware failure. So check temperatures first, if OK, load default settings in the BIOS (and make sure, that the CPU is running at default speed with that, some motherboards oveclock even with default settings). If still unstable, check for blown capacitors or anything else burned on the mainboard. If still unstable come back and we will think more about it.

EDIT: also allow 100% of CPU time and see what than happens.