If you dropped the instance from the file system (perhaps while DB2 was down with db2stop), then, DB2 still "knows" about the instance because its directories contain a reference to it.
I would perhaps try to uncatalog the instance first (this would remove it from the directories).
Try the following:
db2 uncatalog node <instance name>;
db2 terminate;
And see if that doens't help. You may also need to remove the instance definition from the DB2 registry:
# make sure there is a space after the equals sign to unassign this variable.
db2set DB2INSTDEF= -g
db2stop
db2start
As with anything, try to take a backup of everything before you mess around so you don't make it worse.
Ok...I think I have a better idea of what you need based on the comments above.
First off, if all you need it DB2, I'd go download DB2 10.1 Express-C (the link will take you to whatever is the latest at the time. At the time of this post it is 10.1 Fix Pack 2) to get you started. It is the same binaries as Enterprise Server Edition. All you need to do is purchase a license from IBM and apply it using db2licm -a <license file name> in order to turn your Express-C into Enterprise Server Edition. Now, that aside, since you are installing this on Windows, make sure you download the appropriate bit version (ie, 32 bit vs 64 bit).
Also, and this from my experience on Windows, make sure you install the 64 bit DB2 into Program Files (no matter which drive you install it to) and if you install the 32 bit DB2, install it into Program Files (x86) (on a 64 bit OS). If you don't do this, Windows won't find the DB2 drivers for any ODBC connections you wish to set up. And even with that, I've had hit and miss luck with 32 bit DB2 on 64 bit Windows.... Best to just use 32 bit DB2 on 32 bit Windows and 64 bit DB2 on 64 bit Windows.
Ok...whew! Now that aside, once you install DB2, it will automatically create an instance named DB2 and most likely create a database called SAMPLE (which you can always remove).
I've found it best (and this is just me) to use a system or local account for the admin ID for DB2. Either way, make sure you let DB2 create the DB2ADMNS and DB2USERS groups. Anyone you want to be able to maintain DB2 will need to be in the DB2ADMNS group and obviously if you just want to access DB2 in the DB2USERS group.
DB2 automatically comes with the DB2 Control Center,which is clunky as all get out. But don't let that turn you off. That is just a GUI, the actual database itself is amazingly fast and powerful. Besides as of version 9.5 or 9.7, IBM has deprecated the Control Center. They still have packaged it with DB2, but they really recommend that you download IBM Data Studio, which is a free, Eclipse-based product that you can use to interact with DB2. I recently downloaded it and tried it. I love it waaaaay better than Control Center. We (the DBAs at our company) are going to work on a project to roll out Data Studio to replace end user and developer access to DB2 to move away from Control Center.
When you download Data Studio, pick the "full product image" under the "Optional Downloads" section. It should be the one about 1.5GB rather than the one above that is only 112MB.
Anyway, hope this gets you started. Let me know if you have other questions.
Best Answer
If you only need them to be an administrator of the database, you can grant them DBADM authority.
Set up an AIX or LDAP group for your admins and then assign them to that group. Then run the above command to assign the admin authority to that group.
Some further information for you: If you have 9.7 or higher, then you can separate out other authorities such as granting
DBADM WITHorWITHOUT DATAACCESSandWITHorWITHOUT ACCESSCTRL(WITHis the default). There is also the SECADM authority.To grant everything under 9.7 or higher to mimic what you would have received in lower versions of DB2 then
If you are talking about instance authorities, then you can add them to the groups that are assigned to the
SYSADM,SYSCTRL,SYSMAINT, orSYSMONDB2 groups. (Although it sounds like you don't want that. I am merely mentioning it for holistics.)For a good overview of DB2 priveleges, I would recommend checking out the Authorities Overview page in Information Center.