Yeah, but it depends on what was written and where. If the OP had, for example, a 100GB hard drive, and 50GB was data, the BT4 install should have only installed the BT4 4GB+ of data, leaving some remaining 45GB+ relatively intact. The format would have changed on the partition of course, but there are some tools that will still pull out some data. It's worth a try, if he really "had all my life in that computer!!"
Of course a backup might have helped, too.
So today's lesson are:
1) Don't **** around with installs that you clearly don't understand.
2) Always RTFM.
3) Backup. Backup. Backup.



Or using some kind of software that will write random bits all over the drive, that should work to make it impossible to retrieve your personal data.

