Был собран карантин файлов, по которым проехались пачкой антивирусов и в файлах не найдено зловредов.
Проблема осталась.
У кого какие есть соображения по этому счёту?
Сделал chkdsk c:
Код:

Checking file system on C:
The type of the file system is NTFS.
Volume label is Windows Universe.
A disk check has been scheduled.
Windows will now check the disk.
CHKDSK is verifying files (stage 1 of 5)...
256768 file records processed. File verification completed.
198 large file records processed. 0 bad file records processed. 66 EA records processed. 67 reparse records processed. CHKDSK is verifying indexes (stage 2 of 5)...
327222 index entries processed. Index verification completed.
CHKDSK is scanning unindexed files for reconnect to their original directory.
1 unindexed files scanned. Recovering orphaned file Speech (426) into directory file 3644.
0 unindexed files recovered. CHKDSK is verifying security descriptors (stage 3 of 5)...
256768 file SDs/SIDs processed. Cleaning up 4029 unused index entries from index $SII of file 0x9.
Cleaning up 4029 unused index entries from index $SDH of file 0x9.
Cleaning up 4029 unused security descriptors.
Security descriptor verification completed.
35228 data files processed. CHKDSK is verifying Usn Journal...
35180896 USN bytes processed. Usn Journal verification completed.
CHKDSK is verifying file data (stage 4 of 5)...
256752 files processed. File data verification completed.
CHKDSK is verifying free space (stage 5 of 5)...
29205040 free clusters processed. Free space verification is complete.
CHKDSK discovered free space marked as allocated in the
master file table (MFT) bitmap.
Correcting errors in the Volume Bitmap.
Windows has made corrections to the file system.
218998047 KB total disk space.
101724476 KB in 157260 files.
86432 KB in 35229 indexes.
0 KB in bad sectors.
366979 KB in use by the system.
65536 KB occupied by the log file.
116820160 KB available on disk.
4096 bytes in each allocation unit.
54749511 total allocation units on disk.
29205040 allocation units available on disk.
Internal Info:
00 eb 03 00 f4 ef 02 00 60 01 05 00 00 00 00 00 ........`.......
48 02 00 00 43 00 00 00 00 00 00 00 00 00 00 00 H...C...........
00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 ................
Windows has finished checking your disk.
Please wait while your computer restarts.