Thank you very much for your responses, I really appreciate them. Sorry for the delay, my pc is out of order as explained further below.
Lenovo Thinkcentre A57, model 9702AB7.
SOMETHING NEW OR DIFFERENT:
- One odd thing I'd recently noticed maybe 2 days before the problem started, is that an installed virtual CD/DVD program, although isn’t in use, used to appear in the Processes of Windows Task Manager but stopped coming. On July 18th I noticed that the process is active again. (I´m used to opening Windows task manager on a daily basis because my pc is very slow, as to manually stop any process as needed.)
- Another odd thing: My PC has Vista-Linux dual-booting, controlled by Vista. Right after the Vista problem began, I tried to boot into Linux with no success, and so remains as of today. Can't tell when this problem started, because I hadn't booted into Linux since several days ago. (The Vista bootloader, by using a 3rd party program, correctly presents the screen of menu to select either Vista or Linux; once selected Linux, the first, never seen before by me, Linux text-mode screen hangs, and ctrl+alt+del restarts. I haven't focused on the Linux problem yet, waiting to solve the Vista one first.)
- After the problem started and just to be sure, two days ago (July 16) I ran my installed anti-virus, anti-malware and a couple of online scanners The following three threats were detected in their respective files, by three different scans:
- “Name: Trojan.Win32.Generic!BT.” (The respective file wasn't or isn't in use)
- “Description: Virus/Trojan, Type: Trj/CI.A, Active: No, Disinfected: no.” (File wasn't or isn't in use)
- “Description: a variant of Win32/InstallCore.D. Action taken: Cleaned by deleting - quarantined.” (File recently had been used once unintentionaly, never used before.)
SHUTDOWN FROM SAFE MODE:
Yes, the system shuts down properly from safe mode.
Ran chkdsk /r, exited Dos prompt, clicked the reboot instruction on Windows with no response, then clicked the currently non-working off icon, ctrl+alt+del, and physical switch, then had to make a hard shutdown, and booted. The usual Windows Error Recovery screen appeared, selected Start Windows Normally, but no signs of chkdsk process. I started Dos prompt and an empty Dos screen with just a blinking underscore showed up, no way to type “chkdsk” or “exit” (just to click the closing “X” al the top corner), then another hard shutdown, repeated the above, and same results. (I think that the unfinished shutdown process didn't allow to prepare the chkdsk /r at rebooting.) At the end of the day things got more complicated, as follows.
NEW PROBLEM STARTING ON JULY 18TH, COMPUTER IS OUT OF ORDER:
After a couple of hard shutdowns trying to run chkdsk /r (as described in the preceding paragraph), at an attempt to booting, a new (for me) Windows Error Recovery screen appeared, which indicates:
“Windows failed to start... To fix the problem:
1.Insert your windows installation disc ...
3. Click “Repair your computer”
If power was interrupted during startup, choose Start Windows Normally ...
Safe mode with netwoking
Safe mode with command prompt
Last known good configuration (advanced)
Start Windows normally”
Choosing any of the safe modes from the above menu, the system hangs when the text-mode screen shows loading of drivers and gets to the line: “Loaded: \Windows\System32\crcdisk.sys.” Pressing ctrl+alt+del restarts, and pushing the on/off power button turns the machine off. (No hard shutdown needed.)
Choosing any of the other options, the system hangs at the first graphical screen, the one with the progress bars (Loading Windows, if I remember correctly), and behaves similar to the mentioned above, as if it were stuck at the same line of crcdisk.sys. Similarly, a ctrl+alt+del and on/off button do the same as above, i.e., same cycle repeats with the five options from the menu.
(Haven't done the Windows installation disc repairing that the menu indicates. Fyi, I have a Vista recovery CD rather than the installation DVD if needed.)
(By the way, the former Windows Error Recovery screen I was used to knowing before, is the one with four modes for startup, rather than five, with no instructions for using the Windows installation disc, and hasn't showed up again since the new problem arose.)
Then, the only way I have to use my computer is via a Linux Live-Cd session.
So now I need new help please, in order to get back to my normal life. Thanks a lot.
Edited by jaguer, 21 July 2012 - 10:07 AM.