Hi All, I'm at my wits end (or at least my limited fault finding ability...) One of my favourite apps (NETLIMITER) seems to BSOD my new system at random intervals, normally <2hrs after reboot. I have spent hours searching, and trying different things - everthing from RAM testing to switching DEP off. Please can someone offer some suggestions - any help would be appreciated. System CPU : AMD 64 X2 Dual Core Processor 3800+ PSU: Antec 500W SmartPower2.0 Mobo : ASUS A8N-SLI DELUXE ACPI BIOS Revision 1016 Video :7800GT Memory : 2x1GB Hynix RAM PC3200DDR-SDRAM Monitor: Samsung 193E HD/DVD/CD: 2X250GB WD2500JS (NVRAID 0), 80GB IDE, LITE-ON LDW-811S, Samsung SH-W162C Other: DVB-T300 Key Software: XP Pro SP2 & updates, ZoneAlarm Pro 6.0.6031, AVG Free Edition, Alcohol120, Netlimiter Pro 2.06 Latest Drivers eg NVDrivers 6.70, NV Display 81.98, BIOS, etc With netlimiter running I regulargly get BSOD with EventViewer displaying -The bugcheck was: 0x1000007e (0xc0000005, 0xb81c9168, 0xba6bfbf0, 0xba6bf8ec) with BSOD referencing nltdi.sys (netlimiter). Some Notes (probably unrelated) 1. ZoneAlarm / MagicTune3.6 (Samsung LCD tool) clash and hang my system (unrelated), NO BSOD. 2. With NetLimiter not running my system is relatively stable except for an occassional crash that lists nv4_disp.dll (minidump attached, may be related?) with bugcheck was: 0x1000008e (0xc0000005, 0xbf9ecf7e, 0xaf665824, 0x00000000). 3. I have the same combination of apps installed on my old AMD1.2GHz system and all runs very well (may just have to use the new system as an expensive paperweight...) Attaching minidumps with NetLimiter (nltdi.sys)BSOD and NV4_DISP.DLL BSOD Cheers, Davo.