db2 => ? create db
CREATE DATABASE database-name
[AT DBPARTITIONNUM | [AUTOMATIC STORAGE {NO | YES}]
[ON drive[{,drive}...][DBPATH ON drive]]
[ALIAS database-alias] [USING CODESET codeset TERRITORY territory]
[COLLATE USING {SYSTEM | IDENTITY | IDENTITY_16BIT | COMPATIBILITY | NLSCHAR}]
[PAGESIZE integer [K]]
[NUMSEGS numsegs] [DFT_EXTENT_SZ dft_extentsize]
[CATALOG TABLESPACE tblspace-defn] [USER TABLESPACE tblspace-defn]
[TEMPORARY TABLESPACE tblspace-defn] [WITH "comment-string"]]
[AUTOCONFIGURE [USING config-keyword value [{,config-keyword value}...]]
[APPLY {DB ONLY | DB AND DBM | NONE}]]

tblspace-defn:
MANAGED BY { SYSTEM USING ('string' [ {,'string'} ... ] ) |
DATABASE USING ({FILE | DEVICE} 'string' number-of-pages
[ {,{FILE | DEVICE} 'string' number-of-pages} ... ]) | AUTOMATIC STORAGE}
[EXTENTSIZE number-of-pages] [PREFETCHSIZE number-of-pages]
[OVERHEAD number-of-milliseconds] [TRANSFERRATE number-of-milliseconds]
[NO FILE SYSTEM CACHING | FILE SYSTEM CACHING]
[AUTORESIZE {NO | YES}] [INITIALSIZE integer {K |M |G}]
[INCREASESIZE integer {PERCENT |K |M |G}] [MAXSIZE {NONE | integer {K |M |G}}]

config-keyword:
MEM_PERCENT, WORKLOAD_TYPE, NUM_STMTS, TPM, ADMIN_PRIORITY
NUM_LOCAL_APPS, NUM_REMOTE_APPS, ISOLATION, BP_RESIZEABLE.

db2 =>

А ты как ее создаешь? полностью напиши...)

В документации написано:
On the Windows operating system, the path must be a drive letter (for example: C:).