I have a problem I could not find anywhere else. Maybe somebody here has an idea on how to solve it.

I have a MacBook Pro, early 2011, 2.2 GHz i7 with the AMD Radeon HD 6750M and 1680 x 1050 display. I have installed Windows 7 on a partition of the hard drive and have to switch there about once a day. Every single time I switch back to Mac OS X (10.7.2), the computer will freeze either immediately or within up to three minutes after logging in. This is absolutely reliable. I then have to do a hard restart (keeping the on/off button pressed for several seconds), and when the computer comes back, everything works fine until the next time I switched to the Windows partition.

Since this is a freeze, no error report is generated by the system, so the Apple solution is "Send the computer in", something that is impossible for me (I need my MacBook constantly).

I do have quite a few extensions installed, and suspected Quicksilver for a while, but deactivating it did not solve the problem. Other extensions going up at startup are: iCal, Evernote, DoublePane, iTunesHelper, Autograph, DropBox, SophosUIServer. Sophos Anti-Virus is the only program running both in Windows and Mac OS. All software is legal, and virus scans (Sophos and MacScan) showed no Malware.

Any helpful suggestions, what might cause the problem?

  • 2
    "This is absolutely reliable." I can confirm that this happened on my MBP 3,1 with a SSD. The only case where this did not occur is when - instead of rebooting into the other OS - I first shut down completely and manually boot into the other OS. I noticed that Sophos AV was connected to this problem. Uninstall it using the Sophos Uninstaller.app and report back.
    – gentmatt
    Commented Jan 12, 2012 at 10:49
  • I have to apologize for the delay, but I tried what you suggested, and the short answer is: It seems to have solved the problem. Thank you. The longer answer: It took a while, since the very last time I had Sopohos running, it suddenly announced that it had found a virus (FakeAvCn-c), right before it crashed. So I got a few other virus scanners, and checked all partitions of the hard drive repeatedly, both in Windows and Mac OS. No luck, so I assume it was a false alarm caused by whatever caused the crashes as well. Anyway, it seems that you should not run Sophos Antivirus with BootCamp... Commented Jan 15, 2012 at 15:58
  • Good to hear! I'm glad that I could help you.
    – gentmatt
    Commented Jan 15, 2012 at 18:37
  • Not what you asked, but re: I have installed Windows 7 on a partition of the hard drive and have to switch there about once a day - if you're using it that often, you could consider using Parallels or VM Fusion to save a lot of rebooting Commented Feb 5, 2015 at 2:46

1 Answer 1


My Mac (OS X Mavericks 10.9.4) also crashes/freezes and becomes partly or wholly unresponsive (beach ball and all) and it was due to Sophos Anti Virus. Uninstall it and see if it makes things work!

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