At a fairly new dentists office client of mine this week, their Symantec Corp Edition licensing ran out on their 20 node Win2K Server based network, so I replaced it with NOD32 Ent Edition. That evening I was also pushing the envelope...upgrading two of their main software packages, PracticeWorks and Dexis. So I was going around each workstation uninstalling SAV, and actually running the client install of NOD32 and plugging in the managed info so the RA Console would pick them up...since I was sitting down at each workstation several times that evening anyways. One workstation...this one was slightly older, Win2Kpro, SP4 and all updates, hung on shut down immediately after installing NOD32. Startups....took forever to get to the login, (like literally 30 minutes)...and once logged in, no matter what profile, it'd not make it to desktop. Safe mode would work only with a local login, no network support safe mode. Uninstall NOD32, problem went away. Install NOD32..problem came back. Event viewer was filled with errors like 7001 and various related ones, svshost and RPC and all sorts of other related cascading errors. Ran an online scan, clean, ran malware removal tools, clean. Google was rather dry...but one forum pointed to a link from troubleshooting these errors in Win2K....pointing to a Microsoft KB article about Lexmark printer drives. I look over to the right, this computer has a Dell AIO a940 connected to it, via USB. "Who makes Dells printers?" Lexmark of course. So I uninstall the drivers, unplug the printer, bounce the rig, NOD32 installs and the machine reboots without a hitch. I go and download the latest a940 drivers from Dell, install those, no further problems. I guess since the networking support was slightly hosed from the old Lexmark drivers, and NOD32 installs some LSP hooks, that caused the big hangups. Anyways, something to file away in your memory banks if you come across this in the field.