Hi everyone,
For the past few days, my PC has been performing too slow. When I check in the task manager it shows that CPU Usage is 100% and the fan inside my CPU keeps making noises and it gets to my nerves..! Recently, I had downloaded a .rm video file which was incomplete(means the download was not completed). I tried deleting this file but it keeps on showing that some prog or person is using the file. I somehow feel that this file might be causing the problem but still I'm not sure about it. In the task man it shows that the process explorer.exe is taking 51 of CPU and the system idle is taking 49 of CPU usage and together they are slowing down my PC..!
I Have a windows XP SP2 running on my PC with 160GB hard drive,533mhz and 512 MB Ram...
Guys... please do suggest me a way out of this Problem... :(

Two possibilities. Try doing a System Retore to before you downloaded the file. Or boot to Safe Mode and delete the file.

As mentioned above, try safe mode and see if you could delete it that way

Try unlocker, right click on the rm file and choose unlock and then unlock all
This should release whatever is holding the program from deleting
UNLOCKER 1.8.5 BY CEDRICK 'NITCH' COLLOMB (http://ccollomb.free.fr/unlocker/)

Here is another one if above doesn't help, Dr. Delete
Dr. Delete - FREE Tool deletes in-use files by scheduling them to be deleted at the next startup. (http://www.docsdownloads.com/Tier1/dr-delete.htm)

Hey...
I tried the system restore twice but it didn't wrk... and so, finally I went to the safe mode and got rid of the pested file for good..! My PC is working fine rite now. Noise made by the fan is gone now... but now in the taskman it shows that System idle process is taking 99 CPU Usage... would that be a problem? Though the system is not slowing down anymore...
Anyway... thank you guys...

That's normal. The system Idle process means you have that amount of your CPU unused. It's IDLE, which means Unused.

Okkk... thank you once again guys...
Its truly a relief for me now..!