IRQL_DRIVER_LESS_THAN_OR_EQUAL are 0xA errors and these are normally caused by hardware issues. But as KurrentEweser rightly points out we need to know what other errors you are getting.
Here are a few steps you can do:
1. Run memtest on your RAM for a minimum of 7 passes (there are 8 individual tests per Pass). This runs at boot-up. If you have any errors you have corrupted memory that needs to be replaced. Plus, you'll need to run this test per stick to determine which one(s) need to be replaced.
Memtest86+ - Advanced Memory Diagnostic Tool
2. Run a full harddrive diagnostics. You can get a free excellent utility from Seagate called Seatools. Run both the S.M.A.R.T. and Long tests, especially the Long.
3. Check the voltage settings on your memory.