Hi, having a problem with my laptop, was originally a vista machine but purchased windows 7 and installed as a fresh copy. All installed ok but when i do the windows updates and system restarts, it always goes into start up repair mode and fails. the error in the log says mpfilter.sys is corrupt. I did run the pc for a couple of months without doing any updates and it was fine, as soon as updates were installed it no longer worked. I don't know what this is or how to fix it. Any help would be much appreciated. Thanks in advance.