All snap-ins missing

​XPS400 2.8Gig 820 D Dual Core -VIIV​
​O/S WinXP Media Center Edition 2005​
​3 G.B. DDR2 RAM PC5300 - 2-1G.B. 2-512M.B.​
​Samsung Hard Drive 250G.B. 7200RPM​
​Seagate externial 320G.B. H.D.7200RPM USB​
​ATI 128M.B.HYPER Mem PCI-E X16 X300SE.DIM​
​ATI TV Wonder Elite PCI​
​19" FP​
​Sigma-Tel Intergrated Audio 7.1 channel​
​Logitech G15 Keyboard​
​DVD-/+RW & DVD-ROM​
​Pertelian X2040 ForeSight Systems LCD information Display​
​Dell 944 AIO Printer​
​Sytem Blower Slot Fan​
​EASYWATCH LCD System Monitor /Fan Controller​

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​ Iam shocked and do not know why ,however when I open the MMC all the snap-ins that once where their are gone . My WMP ver10 will not play any of the pre-installed music video's that use to work ? Iam not sure yet what other applications are going to be effected by this ! For Windows Media Player I was told to search for the .DRM file and there is none on my Drive C , I had a small drive D that I deleted and now Iam thinking the snapins where actually on that drive along witrh some other system files ! When I followed dierections on how to browse the registry and find the location of the WMP .DRM file it said its location was C:, D /Doucuments and settings /All Users ? I may have missed a couple of entries since I did not write the path down ,however when I seen the D listed ,that told why I no longer had the DRM ! Any one who can help me ith this situation without doing a re-install of he O/S it would be greatly appreciated ,if you have any ?'s to futher assit you in helping me ,my factory restore is no longer available ,this is a re-install O/S that a neighbor a PC programmer did for me ,however he did such a poor job I had to have Dell support send me instructions on how to reformat ,partition and re-install again ,somehow the drive D survivied al of this however the space used on it was so small I deleted it and now its just a empty partition .5 G.B. in ?​

​ Thank You ,Nick ​