HP Presario CQ1 Upgrading and Servicing Guide - Page 22

22 Return the computer to the upright position. 23 Reconnect any cables that were disconnected for this procedure. Troubleshooting If the computer displays a memory error after you have turned it back on, check the following:  Turn the computer off and unplug the power cord, then open up the memory compartment and make sure the memory card is firmly seated. To install it correctly, make sure it inserted all the way into the compartment and then push down on it to snap it into place.  Verify that the memory installed is compatible with this computer. SO-DIMM modules must meet the following requirements:  200-pin DDR2-DIMM  PC2-4200 (533 MHz) DDR2-SDRAM or PC2-5300 (667 MHz) DDR2-SDRAM  Unbuffered, non-ECC (64-bit) DIMMs  1.8 V memory only  4.0 GB maximum installable memory. Actual available memory that can be used in Windows may be less.  Because the memory uses dual channels, you should use the same DIMM type for both sockets. 24 Plug the power cord into the bottom of the computer. 20 603411-001 - Installing Memory