So far you have worked out that the problem most likely lies in the sound card or its drivers. There are two issues here, though, which are likely to complicate the solution.

To disable a device, clear the Original Configuration(Current) check box

Firstly, you are getting two different symptoms. These may relate to the same problem, but you may have two separate problems. Also, the problem is intermittent, which means with each solution you try you will have to restart your computer repeatedly, testing it for a while each time. You only need the problem to happen once to show that it has not been fixed, but you must leave it a reasonable length of time to convince yourself that the problem has been solved.
What you need to do is eliminate the sound card from the system to see if the symptoms disappear. You could go to Control Panel--System--Device Manager and remove the drivers for your sound card. Unfortunately, because the card is Plug and Play, most likely Windows 95 will attempt to reinstall the drivers next time you restart the computer.
Instead, in the Device Manager, choose Properties for the sound card. In the Device usage section, uncheck the Original Configuration (Current) check box. The device driver will be unloaded and will not load during system start-up. You will have to put up with no sound for a while to see if the symptoms recur.
If you are successful, here are some things you can try to solve the problem permanently. You can reinstall the drivers, as the ones currently being used could be damaged. If this fails, see if you can get updated drivers for the card.
If you solve the system crash problem but not the start-up problem, your sound card may not be initialising properly. Sometimes this can be caused by the card not sitting properly in its slot. I used to have an internal modem which would stop working about once every two months. I had to pull it out of its slot and push it back in. Then it worked perfectly. So pull the sound card out, and put it back again, possibly in a different slot.
System start-up problems can result from cards not working properly. If you have a SCSI card, network card, internal modem etc, you can retry the same diagnostic techniques with each of these, or even try removing the card altogether. If this fails, it is probably time to wipe the hard drive and reinstall Windows 95. This can be the surest way to determine whether it's a hardware or software problem.
- Roy Chambers