Restoring databases when only data file available

shutdown sql

move the current database file or rename it

restart sql server

create a new database of the same name and log file and location as the old database and log file

get rid of the old database.
 you may be able to right click delete it in this situation or used sp_removedb

create a new database of the right size and shape with correct log and data file locations

stop sql

rename the new databases.mdf or delete it if you don't have enough space - do not touch the .ldf

move back in the old database .mdf file or rename it back again

restart sql server

it should come up suspect
--------------------------------
1. From a query window, set the status so that you can update the system
tables by running the following query:
use Master
go
sp_configure "allow", 1
go
reconfigure with override
go
 
2. Then set the status of the DB that is giving you the problem (XXXXX) into
Emergency Mode by running the following query:
 
update sysdatabases set status = 32768 where name = '<DBName>'
go
checkpoint
go
shutdown with nowait
go
 
3. Go into the data directory (MSSQL7\DATA) and rename the log file associated
the DB in question (XXXX.ldf) to some 
temporary name, such as XXXX.TMP.
 
4. Exit the query window.
5. Then start up SQL Server from a DOS command window by issuing: 
sqlservr -c -T3608 -T4022.
6. Bring up another query window and verify that the DB is in emergency mode
by issuing:
select Name, Status from Sysdatabases where name = '<DB_Name>'
 
7. Verify that the status is 32768. If it is, then issue the query:
dbcc traceon(3604)
dbcc rebuild_log ('<DB_Name>','<log_filename>') <--- You will need 
the quotation marks 
REBUILD_LOG should take less than 5 minutes even on a very large 
database. It should complete with the message
DBCC execution completed
8. Take the database out of bypass recovery mode by issuing the command
update sysdatabases set status = 0 where name = '<DBName>'
9. Exit the query window and then shutdown (Ctrl-C in the DOS window) and
restart SQL server. Verify the status of the 
database by running DBCC NEWALLOC and DBCC CHECKDB on the database.