The problem described by the customer is an unusual one because it has multiple BSOD with different errors and it shows multiple hardware failures.
These problems occur when the PC has been used for several hours especially in gaming or other programs , the first BSOD was with the error DRIVER_IRQl_NOT_LESS_OR_EQUAL, this error sounds like a simple drivers issues so I advised the customer to update the drivers or reinstall them using another version but the next BSOD was somehow different than the first one with the error CDD.dll which may include a Windows error or a registry error so this time I recommended a program that can search corrupted registries and so on.
The customer uses Linux also so when a big problem appeared in Ubuntu also there was no doubt a hardware problem this problem consists in the machine freezing and at that freeze the sound coming from the speakers was some sort of annoying buzz.
Before the customer reached me he used Windows at that time and another BSOD occurred and this one was with a serious warning page_fault_in_nonepaged_area this error occurs when there is a big hardware problem so I started using some diagnostic tools for example I used chkdisk for corrupted sector or files in the HDD and the result was unexpected everything was ok next component checked was the RAM memory with memtest and the result was unexpected again everything is working fine but then I remembered a small detail that the customer said that the PC just before BSOD or the freeze some annoying sound was coming from the speakers so maybe a hardware problem did exists with the sound card so in the next test I disabled the sound card and no more BSOD and no mere freezes , interesting then I enabled the sound card but with no drivers installed and again BSOD so I recommended the customer to buy a USB sound card and since then the computer is free of BSOD or freezes.
A job well done even if it was a unusual problem.