Are you having troubles getting Steam to boot up today? If so, the problem might not be with Valve's blockbuster gaming service; the issue could be your antivirus, instead. This weekend, the freebie Avast! antivirus misidentified a Steam component as a nasty little Trojan and sent the executable to the time-out box known as Quarantine as a result. The problem: SteamService.exe was a totally clean file, and Steam won't run without it.
Fortunately, the muck-up only lasted about an hour and a half, according to The Register. Avast! yanked the bonked definition around 90 minutes after it went live. While the goof shouldn't have happened in the first place, kudos to Avast! for fixing so quickly, and on the weekend to boot.
If you were affected, restoring the file from Quarantine might get Steam up and running again. However, several Steam users needed to reinstall the service, resubmit their verification code and reboot their PC to get Steam working normally again, and many warn that installing SteamService.exe again can be a lengthy process.
Where you affected by Avast's false positive? How easy was it for you to get Steam up and running again?