Hi 2All,
Mostly, I’m very, very 
at having found this thread cuz it answers about 3-4 months’ worth of issues for me, so this is mainly intended for pk (?) and/or Alwil. BTW, really sorry 4 endless length(4 months of frustration=a lot of vocab!)I have done FOUR “clean” installs of W7 x64 HP since purchasing Avast IS. The 1st x was due to avast’s fw causing sys instability when running mem-intensive programs, but that was really “mea culpa,” as I didn’t verify driver’s 64-bit compat prior to install of suite. Since that 1st clean install, I’ve been using avast’s free av. But I kept encountering perform. issues which an Intel Core i5, x64 arch. w/HypTh & 8 Gigs of DDR 3 installed RAM & storage capacity=1 TB should not be having. Just after clean install, all’s hunky dory, then slowly, steadily, it goes downhill from there. Browsers, esp. IE, freeze after an hour or so, or else it “hangs” while attempting to open (always a fun game 2 play w/browsers). And then it’s WExplorer’s turn to start acting up…I love seeing halved UI’s! But then the Really good part comes next. I do a SysRestore,& when my OS shows my dsktp once more, I get an “extra” w/it that says SysRestore was a pointless waste of both our times and nothing has been changed except logging of another error code (I’m paraphrasing, of course) Then it suggests my AV might be culprit, so now I try restore w/Avast realtime scanner turned off or in “Safe Mode” or w/it off during creation of restore point, etc.,and then…NOTHING! well, I guess a black screen [OD] is actually a “something.” Then I try to recover my OS. But it doesn’t happen, and I do the clean install (at least W7 installs relatively quickly).
I wasn’t even really looking for a solution via this forum since I’ve spoken to Avast Support many x & was told it wasn’t faulting of their sw. As I’m sure you all know about MS’s SysInternals tools, all I have 2 say is Thank you ‘Autoruns’. Turns out that in > c:\windows\system32\drivers.…there are a few drivers installed I did’t know about, e.g., “aswRdr” aka avast! TDI Redirect driver or “aswMonFlt,” aka avast! mini-filter driver or “aswSP,” the driver for avast’s self-protection module, the point being: you CANNOT run 32-bit drivers w/64-bit hardware! Ever! Isn’t that common-know or if not, shouldn’t Support at least know? These are not the type of drivers that Win7 displays in Device Manager (not a techie so I wouldn’t know what 2 even watch for)& maybe it’s my fault for not hunting around my registry for rogue 32-bit drivers & I admit it didn’t even occur 2 me to think prog installed drivers for av too, but during my converses w/avast support, it might have been nice if someone had said something somewhere along the line. Even if this isn’t the root cause, after troubleshooting w/Support, I decided to just use AV part of sw & didn’t req’st refund as it’s really my prob 4 not confirming driver-compat. But can’t help wondering why they didn’t bother to tell me about the av drivers? Sure it was only $60.00 or so, but in a world where the OpenSource/GPL/Freeware can be just as good (note:avast free av), that I paid for security sw & got !@% really makes me ??? & a bit >:(. Any recommends for 64-bit compatible (good) AV would be greatly appreciated ;D
BTW, does anyone know if they’re currently offering free upgrade to x64 avast IS - it’s already paid for, I might as well use it. Thnx (& :-[) to anyone nice enuf to have read thru this post or who just had nuttin’ better to do.