I can't install MS hotfixes, via any means, on a live XPSP3 system. nLite has not been used. I've deleted %windir%\system32\catroot2, re-registered the PKI DLLs, stopped and started CryptSvc, cleaned up old KB* .cat files in %windir%\system32\catroot, emptied %windir%\SoftwareDistribution-- all the usual suspects. I've monitored the installs with ProcMon and even DbgView. There's just nothing obvious going on. Here's the common thread in all the hotfix installer logs (using the exFAT hotfix as an example): 2.172: Drive C: free 42915MB req: 32MB w/uninstall 0MB 2.172: Share \\.\nul\: free 0MB req: 27MB w/uninstall 0MB There are a lot of other references to "\\.\nul\" and a lot of failures to stat files located there and so forth. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Setup looks sane. I've actually replicated this problem on another laptop with a similar (corporate IT) preinstalled XP image. Mostly the image means that McAfee (various modules) and PointSec are in the way. I can't remove or disable them, even momentarily. This problem started immediately after installing the latest batch of MS hotfixes (some critical, some optional, all XP) via MS Update. Unfortunately, I'm not sure which ones, and there were about thirty total (corp IT didn't apply them before handing out the machines). Any help at all appreciated. -Rebecca