Did you try TRUNCATE
- this will delete everything.
TRUNCATE TABLE yourTable
from MSDN
TRUNCATE TABLE is similar to the DELETE statement with no WHERE clause; however, TRUNCATE TABLE is faster and uses fewer system and transaction log resources.
Compared to the DELETE statement, TRUNCATE TABLE has the following
advantages:
Less transaction log space is used.
The DELETE statement removes rows one at a time and records an entry
in the transaction log for each deleted row. TRUNCATE TABLE removes
the data by deallocating the data pages used to store the table data
and records only the page deallocations in the transaction log.
Fewer locks are typically used.
When the DELETE statement is executed using a row lock, each row in
the table is locked for deletion. TRUNCATE TABLE always locks the
table and page but not each row.
Without exception, zero pages are left in the table.
After a DELETE statement is executed, the table can still contain
empty pages. For example, empty pages in a heap cannot be deallocated
without at least an exclusive (LCK_M_X) table lock. If the delete
operation does not use a table lock, the table (heap) will contain
many empty pages. For indexes, the delete operation can leave empty
pages behind, although these pages will be deallocated quickly by a
background cleanup process.