I'm not able to run the wallet. After that notification it crashes. Looking in the AppData\Roaming\tekcoin folder I have deleted the "blkindex.dat", but that doesn't resolve the issue. I have tried to delete everything, except wallet.dat, and have file "blk0001.dat" that will not allow me to delete it. So at this point I'm about to safe mode and scrub the .dat file.
Make a copy of wallet.dat and tekcoin.conf, put them in a safe place.
Reboot to make sure that all wallet processes are stopped.
Delete EVERYTHING in the tekcoin folder.
copy wallet.dat and tekcoin.conf to the folder
restart the tekcoin-qt client.
last step? Wait. A while. It can take several hours to sync
There is also a bootstrap available which will shorten the time. I personally favor syncing from zero, but I'm paranoid. Your mileage may vary on that 