Today I installed Windows XP professional on a Intel RC440BX system with Intel Pentium III 450MHz processor, 256 MB RAM (2x128 SDRAM), 40GB HDD, and everything seemed to be OK (after installing Office 2003, AVG antivirus, Adobe Reader, WinRAR, Quiktime) until the system started to close open windows unexpectedly. It was quite wird, for example I went to defragment the hard drive and when I started it closed that window. Also when I went to device manager to take a look at that it closed that window unexpectedly. I restarted the system and tried to do the same and it continued closing windows. I realized it did that when more than two windows are opened, e.g. Control Panel+System properites+Device manager. My question is: Is it virtual-memory related or it is something else?. Whatever it is, would you please, spare me the possible solution. Please, Help!!!. Thanks a lot in advance!