Hi I'm booting to a black screen with mouse cursor in Win7, Any of the safe mode options yield the same result. I am able to bring up the system recovery options. Unfortunately, system restore yields no restore points...seems extremely odd, and Startup Repair says it cannot make any repairs due to OsVersionMismatch...screen shot below. Just prior to this I was having system lock-up issues. Upon running chkdsk /f, the utility ran for several hours stating "Replacing invalid security ID with default security ID" for over 250,000 files. Any ideas?