I have a working built in microphone but it is not there in the options to select the microphone to enable it.. please help!!

here is my system info:

Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

C:\Users\Akshay>systeminfo

Host Name:                 AKSHAY-PC
OS Name:                   Microsoft Windows 7 Home Premium
OS Version:                6.1.7601 Service Pack 1 Build 7601
OS Manufacturer:           Microsoft Corporation
OS Configuration:          Standalone Workstation
OS Build Type:             Multiprocessor Free
Registered Owner:          Akshay
Registered Organization:

Original Install Date:     7/10/2012, 2:48:02 PM
System Boot Time:          10/3/2012, 2:20:01 PM
System Manufacturer:       Dell Inc.
System Model:              Inspiron 1525
System Type:               X86-based PC
Processor(s):              1 Processor(s) Installed.
                           [01]: x64 Family 6 Model 23 Stepping 10 GenuineIntel
~1188 Mhz
BIOS Version:              Dell Inc. A17, 10/27/2009
Windows Directory:         C:\Windows
System Directory:          C:\Windows\system32
Boot Device:               \Device\HarddiskVolume2
System Locale:             en-us;English (United States)
Input Locale:              en-us;English (United States)
Time Zone:                 (UTC-08:00) Pacific Time (US & Canada)
Total Physical Memory:     3,574 MB
Available Physical Memory: 1,981 MB
Virtual Memory: Max Size:  7,146 MB
Virtual Memory: Available: 4,961 MB
Virtual Memory: In Use:    2,185 MB
Page File Location(s):     C:\pagefile.sys
Domain:                    WORKGROUP
Logon Server:              \\AKSHAY-PC
Hotfix(s):                 94 Hotfix(s) Installed.
                           [01]: 982861
                           [02]: KB971033
                           [03]: KB2305420
                           [04]: KB2393802
                           [05]: KB2425227
                           [06]: KB2479943
                           [07]: KB2484033
                           [08]: KB2488113
                           [09]: KB2491683
                           [10]: KB2492386
                           [11]: KB2502285
                           [12]: KB2503665
                           [13]: KB2505438
                           [14]: KB2506212
                           [15]: KB2506928
                           [16]: KB2507618
                           [17]: KB2509553
                           [18]: KB2510531
                           [19]: KB2511250
                           [20]: KB2511455
                           [21]: KB2515325
                           [22]: KB2522422
                           [23]: KB2529073
                           [24]: KB2532531
                           [25]: KB2533552
                           [26]: KB2536275
                           [27]: KB2536276
                           [28]: KB2541014
                           [29]: KB2544893
                           [30]: KB2545698
                           [31]: KB2547666
                           [32]: KB2552343
                           [33]: KB2560656
                           [34]: KB2563227
                           [35]: KB2564958
                           [36]: KB2567680
                           [37]: KB2570947
                           [38]: KB2579686
                           [39]: KB2584146
                           [40]: KB2585542
                           [41]: KB2604115
                           [42]: KB2618451
                           [43]: KB2619339
                           [44]: KB2620704
                           [45]: KB2620712
                           [46]: KB2621440
                           [47]: KB2631813
                           [48]: KB2633171
                           [49]: KB2633952
                           [50]: KB2640148
                           [51]: KB2644615
                           [52]: KB2647753
                           [53]: KB2653956
                           [54]: KB2654428
                           [55]: KB2655992
                           [56]: KB2656356
                           [57]: KB2656373
                           [58]: KB2656411
                           [59]: KB2658846
                           [60]: KB2659262
                           [61]: KB2660075
                           [62]: KB2660649
                           [63]: KB2667402
                           [64]: KB2676562
                           [65]: KB2677070
                           [66]: KB2679255
                           [67]: KB2685939
                           [68]: KB2686831
                           [69]: KB2688338
                           [70]: KB2690533
                           [71]: KB2691442
                           [72]: KB2695962
                           [73]: KB2698365
                           [74]: KB2699779
                           [75]: KB2705219
                           [76]: KB2709630
                           [77]: KB2709981
                           [78]: KB2712808
                           [79]: KB2718523
                           [80]: KB2718704
                           [81]: KB2719857
                           [82]: KB2719985
                           [83]: KB2729094
                           [84]: KB2731847
                           [85]: KB2732059
                           [86]: KB2732487
                           [87]: KB2732500
                           [88]: KB2735855
                           [89]: KB2736233
                           [90]: KB2741355
                           [91]: KB958488
                           [92]: KB976902
                           [93]: KB976932
                           [94]: KB982018
Network Card(s):           3 NIC(s) Installed.
                           [01]: Marvell Yukon 88E8040 PCI-E Fast Ethernet Contr
oller
                                 Connection Name: Local Area Connection
                                 Status:          Media disconnected
                           [02]: TAP-Win32 Adapter V9
                                 Connection Name: Local Area Connection 2
                                 DHCP Enabled:    Yes
                                 DHCP Server:     10.11.218.205
                                 IP address(es)
                                 [01]: 10.11.218.206
                                 [02]: fe80::88f6:85b:a9e:4fbe
                           [03]: Dell Wireless 1505 Draft 802.11n WLAN Mini-Card

                                 Connection Name: Wireless Network Connection 2
                                 DHCP Enabled:    Yes
                                 DHCP Server:     192.168.1.1
                                 IP address(es)
                                 [01]: 192.168.1.103
                                 [02]: fe80::1592:f01f:bc19:141b

C:\Users\Akshay>