SQL: System locks up and runs slow after performing simple DML record insert

SQL Version:  2008 R2

I am having a serious problem.  I ran the following code to perform a simple table record insert which ran successfully.  However, after running this code I could no longer access the related table.  I couldn't run a query against it.  I tried to delete all the records and that wouldn't work either.  When attempting to run any DML statements (i.e. Select * From vPCCertificateTypes) against this table SQL gets locked up and never returns anything and no error messages.  I have to manually stop the query.  Now the entire SQL system is running slow.

Any help would be greatly appreciated.  The code I ran to originally insert the records is below.

Regards,

Bob Sutor

CODE: 

Begin TRAN
 INSERT INTO vPCCertificateTypes (VendorGroup, CertificateType, Description, Active, Category)
 
 SELECT HQCo, 'MBE', 'Minority-owned Business Enterprise', 'Y', 'Affirmative Action' 
 FROM HQCO
 Where HQCo IS NOT NULL
  AND HQCo <> 100
  AND HQCo <> 99
 IF @@ROWCOUNT <> 44 ROLLBACK ELSE COMMIT

Bob Sutor