I am not familiar with 'data collection' in the context.
A query can be read only if it uses an aggregate (or GROUP, or Crosstab, or
DISTINCT), a join which is a non equi join, is an UNION query, uses a
sub-query not updateable itself, as well as and other cases too. If the
query is not updateable, you cannot delete neither modify existing data
through the query (but can by accessing the tables themselves). It may also
be that your database support is read only (DVD, file with the operating
system attribute of read only set, or you don't have necessary user access
to the 'file' supporting the data, or the table is a linked one, and does
not allow update). You may also ends up with a Access being open with a Read
Only access (because the same file is exclusively open by someone else, or
because you specifically asked to open it in Read Only mode).
Vanderghast, Access MVP