Error messages! ARGH!

I get these three error messages at startup:

Error Starting Program

A required .DLL file, PSAPI.DLL, could not be found.
--

Error Starting Program

A required .DLL file, MSTO32.DLL, could not be found.
--

RUNDLL

Error loading msconfd

The system cannot find the file specified.
--

Whemn I clicked the "Start" button, I got this:

Explorer

This program has performed an illegal operation and will be shut down.

If the problem persists, contact the program vendor.

When I clicked on Details, I got this message:

EXPLORER caused an invalid page fault in
module <unknown> at 0000:01741290.
Registers:
EAX=0080ef18 CS=015f EIP=01741290 EFLGS=00010206
EBX=004419d0 SS=0167 ESP=0080ef0c EBP=0080f12c
ECX=bfb74040 DS=0167 ESI=bfb7402c FS=1c5f
EDX=81b00000 ES=0167 EDI=00000001 GS=2616
Bytes at CS:EIP:

Stack dump:
bfbcc34e 0080ef20 bfb7402c 00000000 0080ef20 33454c4f 4c442e32 0000004c 00000000 00000000 00000000 00000000 004419d0 5600c84d 00000000 00000000

Everything then disappears off my desktop when I close the message!

Can anyone help? Is it because my Gateway computer was built last millennium (I got it in 1999)? It has Windows 98.

Boot into Safe Mode then do a virus scan before rebooting normally- you have a virus. http://securityresponse.symantec.com/avcenter/venc/data/trojan.bookmarker.html

You can download psapi.dll if needed at: http://www.dll-files.com/dllindex/dll-files.shtml?psapi

On edit: You can invoke the Startup Menu (for Safe Mode) by hitting F8 as the startup POST is finishing. NOTE: F8 sometimes invokes a selective bootup menu- gives you the choice from which device to boot from, such as floppy, hard drive, cd, etc. Select hard drive then hit F8 again as soon as you're out of this menu.

Shuld I save them to a disk just in case?

if you do a backup and then a virus cleanup, don't forget to scan your backup disk after you're done, because a virus can travel.

That can be throughout your computer, or just in a few programs. If you save files to disk, you may inadvertently save and reapply the little pos that has caused this.

When it happened to me, I had to reformat. The 2nd time it happened , I reformatted. The 3rd time it happened, I found three programs that had been affected (Nvidia, WMP, and ZA) removed, then reinstalled them. The Nvidia one was obvious (video driver. resolution dropped to 100x50, just about). The ZA Pretty obvious too (updating to ZAPro 5 was the cause of it). WMP-not so.

System restore-you can try it, but generally doesn't work, because your .dll stuff has been disappeared.

Good luck. When you get the shit restored, read angry girl's thread about safely surfing the internet, and take the advice offered there. it is very good.

The reference to "Error loading msconfd" is a direct and specific reference to an existing trojan horse. There are instructions on the Symantec link for removing it. If after doing a virus cleanup the DLLs are still missing, they can be searched for and replaced either from the install cd or the internet.

The virus cleanup may or may not stop the problem, but it's the first step in attempting to save the system.