MSCache is not part of the Win Me operating system but rather a Trojan horse.
For details see
http://securityresponse.symantec.com/avcenter/venc/data/downloader.mscache.html

The issue is that you may not have an antivirus application installed equipped
with an updated set of viral signatures and may not be regularly scanning your
system for unwanted guests such as viruses, trojans, worms, parasites and
other scumware.

If you haven't already done so I would strongly recommend that you check your
system for possible viruses using your preferred anti virus application
equipped with an updated set of viral signatures.  However you might first
want to check your PC using one of the online virus checks such as McAfee's
online checker  (http://us.mcafee.com/root/mfs/default.asp)  or Trend Micro's
Housecall (http://housecall.antivirus.com).

I would also urge you to check for possible commercial parasites, spyware and
other assorted adware.  This might be a good time to download yourself a  copy
of the free Ad-Aware 6.0 from Lavasoft
(http://www.lavasoftusa.com/software/adaware/) and also SpyBot
(http://www.safer-networking.org/) and scan your system for and remove all
unwanted parasites, adware and spyware that might be hiding on your PC.
--?
Mike Maltby MS-MVP
mcmaltby@hotmail.com

Are you running anti virus software?  There is a virus
known as Downloader.MSCache.  You can get details on it
at www.synamtec.com