Can Running ComboFix Make the Situation Worse?

sometimes that happens - combofix does a lot... but usually only good things.  

you can have situations where combofix removes a virus that was so embedded, that windows is never the same without the virus.  in some cases, if the virus was a device driver, windows might not even boot up anymore

i haven't seen anything that i can nail down to a specific OS service pack or update, or even specific viruses... just seems to be case by case, you just never know.

i only run combofix when everything else fails, it's either combofix or a reinstall anyway, so can't hurt that much if i've already blocked out the time to do a reinstall

There could be some other reason(s) for system to go slow, however I have never seen Combofix causing system to slow down.

Sudeep

Bryon, curious to know what other anti-spyware programs you run and in what order. In the past I have successfully used Malware Bytes to remove spyware, but in some cases had to also run ComboFix to clean infections that MB did not remove. But now that I've had these 2 negative experiences, thinking I should take your approach and only run CF as a last resort.

Further thoughts ... imho i believe that running ComboFix does present a ~very slight~ risk to a system, but it's a risk worth taking especially when a machine is suspected to be quite infected ....but i'm not aware of any slowness caused by running ComboFix, and it has to date proved to be an excellent tool ... i think of it as being 'one of the big guns' perhaps!

in my first comment where i said :sometimes that happens - combofix does a lot... but usually only good things.  

the intent was "combofix does a lot of things" and not "combofix fails a lot".  combofix is a great tool, but it does have a small percentage of a chance to do more harm than good.  which is probably why you have to keep re-downloading it, since the authors made it expire every few days.

i had one users who was like "wow leave me that program i'll run it every day" i was like, no.

i do it in my order above more because if combofix is going to take 30 minutes anyway, i may as well do it by hand so i can see any other issues along the way... and if that fails, then run combofix which is helpful most of the time

i didnt mention disabling system restore but that's up there too pretty early in the list - i usually don't re-enable it because i can count on one finger all the times it actually worked.

Thanks to everyone who posted their comments. Yeah, I don't know what happened in these 2 instances, but running CF definitely caused the system to slow down even more. Granted, both systems had Windows XP installs that were over 5 years old, which means they were slow & unstable to begin with, but it got worse after CF did its thing.

I'm starting to think that from now on, if I come across a client system w/ a XP install more than 4 yrs old, I'm going to insist on a "backup, wipe & reinstall" approach. Just seems that XP (not to mention Vista) simply become too bloated & unstable after 4 years of use.

Ccleaner would have removed alot of the backup built up over the years...try it you have nothing to loose.

I'm skeptical of the actual value of registry cleaners, but I suppose I could give it a try.

ccleaner does a really decent job, and it DOES ask you if you want to make a backup.reg file of what's going to be whacked.  if bad things happen after the reboot, just click the backup.reg file that was created in 'mydocuments' and it'll put them all back in there

Thank you all.

Thanks!